Method for determining feed quality

ABSTRACT

A method for determining a biomechanical property of a feed using infrared radiation to obtain spectral data on the feed. The spectral data is used to determine the biomechanical property based on the bond energies of the chemical constituents of the feed.

This invention relates to a method for quantifying biomechanicalproperties of animal feed based on a correlation between the chemicaland biomechanical properties of the feed, and to methods for objectivelymeasuring the quality of animal feed, such as fodders including hay,pastures and forages.

Diet is the major determinant of productivity of an animal. In thelivestock industry, animals are farmed for meat, wool and other valuableproducts. The diet of farmed livestock is largely dictated by man and,given the effect of diet on animal production it is highly desirable tooptimize the diet of livestock to gain maximum benefit from the naturalresource.

Feed quality is one variable that has a major impact on animalproductivity. In this respect, feed quality affects the amount of feedan animal will consume and the feeding value it gains from the feedconsumed. In the case of cattle, sheep and other ruminants, feed qualitydepends on digestibility, chemical attributes (nutrient composition) andbiomechanical attributes (namely how easy it is for an animal to chewthe feed during ingestion and rumination).

It is generally accepted that there are constraints on the intake offeed by ruminant animals, that the amount of useful energy obtained by aruminant animal may fail short of the amount that the animal canpotentially use, and that this would result in reduced productivity. Forexample, the principal constraints to voluntary intake of fodders areresistance of fodder fibre to chewing and digestibility (provided thatthe intake is not otherwise constrained by low palatability, deleterioussecondary compounds, or the inadequacy of essential nutrients).Differences between feeds, such as fodders, in their resistance tochewing are reflected in differences in biomechanical properties,including comminution energy, shear energy, compression energy, tensilestrength, shear strength and intrinsic shear strength.

Hay is a common feed and its quality is significantly affected byfactors such as seasonal differences, haymaking practices and pasturecomposition. It has been shown in one recent survey that in some yearsas little as 11% of hay produced was good enough to promote liveweightgain in weaner sheep. This possibility of wide variation in measures ofhay quality is a matter of increasing concern, and has given rise to ademand for a method of objective quality assessment.

A hay quality system adopted in the United States of America uses ameasure known as relative feed value (RFV) to distinguish between haysof different quality. The RFV is calculated from the dry matterdigestibility, which is predicted from acid detergent fibre (ADF)content, and from the dry matter intake, which is predicted from neutraldetergent fibre (NDF) content.

The RFV based system suffers from a number of disadvantages. Forexample, the ADF and NDF contents of fodders are determined by chemicalmethods which take several days to complete, and thus are expensive interms of resources.

While objective quality assessment and product specification has becomean integral part of the production and marketing in domestic and exportmarkets for the Australian grain, wool, meat and dairy industries,performance-based quality standards are not presently in place for feedssuch as hays and other fodders. Consequently;

(a) the feed buyer cannot be sure of getting value for money, and thisis likely to become increasingly important in respect of export marketsif other exporting countries are able to guarantee standards for theirproduct;

(b) the feed producer cannot be sure of getting a higher price for asuperior product;

(c) livestock producers are unable to objectively formulate rations orsupplementary feeding regimes to achieve animal production targets; and

(d) the market for animal feed tends to be unstable.

Whilst the relationship between biomechanical properties of feed andfeed quality is now accepted, there is a need for a convenient,inexpensive and relatively accurate assay method for feed to determineits quality. An accurate determination of feed quality allows foroptimisation of feeding regimes and improved animal production forobvious economic gains.

It is an object of this invention to overcome or at least partiallyalleviate the aforementioned problems and/or reduce the uncertaintiesand concomitant problems of the prior art systems for measuring thebiomechanical properties of feed and hence determining feed quality.

Thus, the present invention provides a method for determining abiomechanical property of a feed, the method comprising the steps of;

(a) subjecting the feed to infrared radiation to obtain spectral data:and

(b) using the spectral data to determine the biomechanical property;

whereby the biomechanical property of the feed is determined on thebasis of the bond energies of the chemical constituents of the feed.

The spectral data may be used directly to determine the biomechanicalproperty of the feed. Alternatively, the spectral data may be used todetermine another property of the feed and the other property is used todetermine the biomechanical property on the basis of a correlationbetween the other property and the biomechanical property.

When the biomechanical property is determined via another property, theother property is preferably a chemical property of the feed such as theADF content or the NDF content or the lignin content.

There is a variety of biomechanical properties of the feed that may bedetermined. Preferably, the biomechanical properties are selected fromthe group comprising shear energy, compression energy, comminutionenergy, tensile strength, shear strength and intrinsic shear strength.

The spectral data may comprise a reflectance spectrum at a combinationof wavelengths or over a predetermined range of wavelengths such as 700nm-3000 nm, or more preferably 1100 nm-2500 nm. Preferably, the dataobtained for the spectral range of 1850 nm-1970 nm is disregarded, thisbeing the range over which water reflects strongly.

The spectral data may be recorded at one or more wavelength intervalsthroughout the spectral range. When the spectral data is a reflectancespectrum over a predetermined range it is preferably measured at 2 nmintervals over the range. Of course, if so desired the spectral data maybe measured at intervals other than 2 nm.

When the spectral data is used to directly determine a biomechanicalproperty, the biomechanical property is preferably determined bycomparison of the spectral data with a calibration equation thatreflects the relationship between reflectance and the biomechanicalproperty. Preferably, the calibration curve is determined on the basisof laboratory data establishing a correlation between reflectance andthe biomechanical property.

Thus, the present invention also provides a method for determining abiomechanical property of a feed, the method comprising the steps of;

(a) subjecting the feed to infrared radiation to obtain spectral data;and

(b) comparing the spectral data obtained in (a) with a calibrationequation to determine the biomechanical property;

whereby the biomechanical property of the feed is determined on thebasis of the bond energies of the chemical constituents of the feed.

The present invention also provides a method for determining feedquality, the method comprising the steps of;

(a) subjecting the feed to infrared radiation to obtain spectral data;

(b) using the spectral data to determine a biomechanical property of thefeed; and

(c) using the value of the biomechanical property obtained in step (b)to determine feed quality;

whereby the biomechanical property of the feed and thus the feed qualityis determined on the basis of the bond energies of the chemicalconstituents of the feed.

In one particular form, the method described immediately above mayfurther comprise the determination of an additional property of thefeed. The additional property may vary and preferably is selected fromthe group comprising the digestibility of the feed in vivo or in vitro,the ADF content or the NDF content, or the lignin content.

The present invention is based on research establishing a strongcorrelation between the bond energies as they relate to the physicalstructure, and the biomechanical properties of feed. Once thiscorrelation is established the bond energies of the chemicalconstituents, and in turn the biomechanical properties of the feed, canbe determined using infrared spectroscopy. The biomechanical propertiesquantified in this way are useful for accurately determining feedquality.

In this respect, research resulting in the present invention has shownthat the biomechanical attributes of feeds such as cereal and legumehays, straws, and mature, dry subterranean clovers are much morestrongly related to animal performance than are digestibility orchemical composition of the feeds.

Thus, comminution energy, the energy required to grind or comminutefodder material, has proved to be a very effective indicator of forageconsumption constraint (FCC), which is the difference between thequantity of forage an animal should consume to satisfy its capacity touse energy (a theoretical maximum) and the actual voluntary dry matterintake achieved.

Shear energy, the energy required to shear fodder material, andcompression energy, the energy required to compress fodder material, aretwo biomechanical feed characters of fodders that are closely related tocomminution energy and which also are good predictors of FCC.

In this respect, feed quality can be assessed in a number of ways. Theforage consumption constraint (FCC) is one convenient measure of feedquality and equates to the difference between the quantity of the fodderthat the animal would be attempting to consume to satisfy its capacityto use energy (theoretical maximum intake) and the voluntary forageconsumption (VFC).

Thus, the present invention also provides a method for determining feedquality, the method comprising the steps of:

(a) subjecting the feed to infrared radiation to obtain spectral data;

(b) using the spectral data to determine a biomechanical property of thefeed, and

(c) using the value of the biomechanical property obtained in step (b)to determine the forage consumption constraint (FCC) or voluntary feedconsumption (VFC) as a measure of feed quality;

whereby the biomechanical property of the feed and thus the feed qualityis determined on the basis of the bond energies of the chemicalconstituents of the feed.

The present invention is based on the finding that variations inbiomechanical properties such as shear energy, comminution energy andcompression energy are reflected in NIR spectra of fodders. Thisfinding, together with recognition of the value of biomechanicalcharacters for the prediction of FCC (and, in turn, the prediction ofvoluntary feed consumption (VFC)) makes it possible for quicker, lessexpensive, more convenient and more reliable prediction of feed qualitythan hitherto known and predicted.

Accordingly, this invention provides a method of (i) assessing thesuitability of a fodder, such as a forage, to meet a required animalperformance; or (ii) predicting the VFC of a forage; or (iii) predictingthe FCC of a forage, which method comprises subjecting a sample of theforage to NIR radiation and determining the reflectance at selectedwavelengths.

It has been found that the biomechanical properties, such as shear andcomminution energy values for a given fodder, correlate with thefodder's reflectance of infrared radiation. More specifically, theinvention is based on research showing that:

(a) NIR wavelengths at which reflectance (R), namely the secondderivative of the logarithm of the inverse of R, correlatessignificantly with the variation in energy required to shear foddermaterials are 1168 nm, 1458 nm, 1598 nm, 1718 nm, 1828 nm and 2048 nm.For the prediction of fodder shear energy (y₁, kJ.m⁻²) the followingequation may be used:

    y.sub.1 =19.95+10239.46R.sub.1168 +3623.49R.sub.1458 -4255.61R.sub.1598 -5319.88R.sub.1718 +5148.38R.sub.1826 +2452.05R.sub.2048

(b) NIR wavelengths at which the second derivative of the logarithm ofthe inverse of reflectance (R) correlates significantly with thevariation in energy required to comminute fodder materials are 1138 nm,2018 nm, 2128 nm and 2408 nm.

For the prediction of fodder comminute energy (y₂, kJ.kg DM⁻¹) thefollowing equation is proposed:

    y.sub.2 =231.42+18224.74R.sub.1138 -4955.12R.sub.2018 -3005.37R.sub.2128 +4290.18R.sub.2408

(c) NIR wavelengths at which the second derivative of the logarithm ofthe inverse of reflectance (R) correlates significantly with thevariation in compression energy are 1268 nm, 1588 nm, 1728 nm, 2278 nm.For the prediction of compression energy (y₃, kJ.kgDM⁻¹) the followingequation may be used:

    y.sub.3 =-0.71-911.04R.sub.1268 +112.57R.sub.1558 -79.48R.sub.1728 -28.02R.sub.2278

(d) NIR wavelengths at which the second derivative of the logarithm ofthe inverse of reflectance (R) correlates significantly with variationin in vivo digestibility of dry matter (DMD) (y₄, %) is 1158 nm, 1238nm, 1668 nm, 1908 nm, 1918 nm, and 2248 nm. For prediction of the DMD(y₄, %) of a fodder the following equation is proposed:

    y.sub.4 =46.62+8162.72R.sub.1158 -8799.69R.sub.1238 +1249.01R.sub.1668 +519.46R.sub.1908 -367.08R.sub.1918 -161.84R.sub.2248

(e) NIR wavelength at which the second derivative of the logarithm ofthe inverse of reflectance (R) correlates significantly with variationin in vitro digestibility of dry matter (IVDMD) is 1698 nm, 1748 nm,1908 nm, 1918 nm and 2158 nm. For prediction of the DMD (in vitro) of afodder the following equation is proposed:

    y.sub.5 =63.43-2186.89R.sub.1698 -1491.99R.sub.1748 +981.30R.sub.1908 -556.01R.sub.1918 +2003.05R.sub.2158

Accordingly, in a preferred method according to this invention, theinfrared wavelengths at which reflectance is measured comprise one ormore of the following: 1168 nm, 1458 nm, 1598 nm, 1718 nm, 1828 nm, 2048nm, 1138 nm, 2018 nm, 2128 nm, 2408 nm, 1268 nm, 1588 nm, 1728 nm, 2278nm, 1158 nm, 1238 nm, 1668 nm, 1908 nm, 2248 nm, 1698 nm, 1748 nm, 1918nm and 2158 nm.

It will be understood that the foregoing are wavelengths at which thestrongest correlations have been observed, and the possibility of usefulcorrelations being observed at other wavelengths are highly likely.

Essentially, it can be shown that in the same way that a decrease incomminution energy is reflected by a decrease in forage consumptionconstraint, there is also a linear relationship between comminutionenergy or shear energy and the consumption constraint of a fodder. Thus,the use of NIR spectra, in conjunction with the equations detailed atparagraphs (a) to (e) above, permits estimation of the VFC of a fodder,which together with estimates of digestibility (conveniently obtainedfrom NIR spectra) can be expected to provide a valuable basis forperformance-based quality standards for fodders.

It is to be appreciated that the intention of this invention is to offera quick, reliable and relatively inexpensive means of obtaininginformation from which the fodder producer and user, such as purchaser,might make informed judgements about the market value of a given foddersample relative to alternatives, and of its suitability for a particularpurpose.

Conceivably, fodder quality predictions obtained by the method of thisinvention could be a useful component of, or used in conjunction with,for example, Decision Support Software (DSS) packages designed to assistlivestock management.

It is further envisaged that by combining NIR measurements made by aremote sensing system, such as Landsat, with data from a GeographicalInformation System, the invention will provide a means of makingreliable predictions of pasture quality. These predictions, togetherwith predictions of feed intake and animal performance, should thenprovide a useful basis for strategies of supplementary feeding toimprove performance in grazing ruminants.

The present invention also provides for a spectrometer configured todetermine biomechanical properties and/or quality of feed according tothe methods of the present invention. Preferably, the spectrometerincludes a data processing means which enables the spectrometer toreceive a feed sample and quantify either or both the biomechanicalproperties of the feed and the quality of the feed. In one particularform the data processing means includes a calibration equation tofacilitate the determination of the feed quality or biomechanicalproperty.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of spectra of samples in the validation andcalibration sets.

FIGS. 2a-2e are graphs illustrating simple linear correlationcoefficient between laboratory determined and NIR predicted values foreach of the biomechanical characters and digestibility of dry matter ofa sample in the validation set.

FIGS. 3a-3e are graphs illustrating simple linear correlationcoefficient between laboratory determined and NIR predicted values foreach of the biomechanical characters and digestibility of dry matter ofa sample in the validation set.

FIGS. 4a-4e are graphs illustrating simple linear correlationcoefficient between laboratory determined and NIR predicted values foreach of the biomechanical characters and digestibility of dry matter ofa sample in the validation set.

FIG. 5 is a graph of predicted voluntary feed consumption versus actualvoluntary feed consumption.

The invention will now be described with reference to the followingexamples. The description of the examples is in no way to limit thegenerality of the preceding paragraphs.

EXAMPLES

The energy of molecular vibrations correspond to the energy of theinfrared spectrum of the electromagnetic spectrum, and these molecularvibrations may be detected and measured in the wavelength range of theinfrared spectrum. Functional groups in molecules have vibrationfrequencies that are characteristic of that functional group and thatare within well-defined regions of the infrared spectrum.

For organic compounds the principal analytical features of the nearinfrared (NIR) spectrum are due to absorbance of radiant energy by bondsbetween hydrogen, carbon, nitrogen, oxygen or with sulphur, phosphorusand metal halides. When organic compounds are irradiated with infraredradiation at wavelengths between 700 and 3000 nm part of the incidentradiation is absorbed and the remainder is reflected, refracted ortransmitted by the sample. Most quantitative reflectance analyses aremade in the wavelength range of 1100 to 2600 nm. The amount of energyabsorbed or diffusely reflected at any given wavelength in thiswavelength range is related to the chemical composition of the organiccompound. NIR spectroscopy uses detectors to measure the amount ofradiation that is diffusely reflected by the irradiated sample.

NIR spectroscopic analysis is an analytical procedure calibrated to aprimary reference method. Calibration in NIR spectroscopy (NIRS) relieson similarities among the spectra, and analytical properties of interestin the reference samples. In this example the analytical properties ofinterest were the biomechanical characters of forages, and the procedurethat was adopted in this example was as follows:

a) prediction of biomechanical characters of a range of grasses usingNIR spectroscopy was established by developing a calibration equation(s)from laboratory determined values of a set of reference samples.

b) validation of the equation(s) either by using laboratory determinedvalues of a separate set of samples, or by a cross-validation procedureusing the laboratory determined values of the reference samples.

c) using the NIRS-predicted values for biomechanical characters of theforages and for digestibility of the forages, forage consumptionconstraint (FCC) was predicted, and in turn voluntary feed consumption(VFC) was predicted.

d) the predicted FCC and VFC were compared with actual data from groupsof animals fed each of these forages.

Example A Developing a Calibration Equation to Predict BiomechanicalProperties of Herbage

The samples used in this example were a range of varieties of Panicumspp. harvested at a range of plant maturities throughout the growingseason (Table 1). Each of the samples was dried and chaffed, and thenfed to groups of sheep (8 sheep per group) which were pennedindividually, to determine in vivo dry matter digestibility (DMD), VFCand FCC. Samples of the hays were stored for laboratory analyses.

Biomechanical properties of the forages were determined using publishedmethods; the energies required to shear or compress the foragesaccording to Baker, Klein, de Boer and Purser (Genotypes of dry, maturesubterranean clover differ in shear energy. Proceedings of the XVIIInternational Grassland Congress 1993. pp 592-593.) and the energyrequired to comminute the forages according to Weston, R. H. and Davis,P (1991) `The significance of four forage characters as constraints tovoluntary intake` p.33 in `Proceedings of The Third InternationalSymposium on the Nutrition of Herbivores` (Compiled by: Wan Zahari, M.,Amad Tajuddin, Z., Abdullah, N. and Wong, H. K. `Published by theMalaysian Society of Animal Production (MSAP). ISBN: 967-960-026-2). Invitro digestibility of dry matter (IVDMD) was determined by thepepsin-cellulase technique as modified by Klein and Baker (Compositionof the fractions of dry, mature subterranean clover digested in vivo andin vitro. Proceedings of the XVII International Grassland Congress 1993.pp593-595.).

There are several ways to process samples for NIRS analysis, and in thisexample the samples were ground through a cyclone mill with a 1 mmscreen and equilibrated at 25° C. or at least 24h before NIRS analysis.The samples were scanned by monochomating near infrared reflectancespectrophotometer (Perstorp NIRS 6500) and the absorption spectrarecorded for the range 1100 to 2500 nm at 2 nm intervals. One spectralrange 1850 to 1970 nm, where water absorbs strongly, was disregarded infurther analysis of the spectral data.

For NIRS analysis the samples were divided into two groups: one group tobe used as a `calibration` set to establish a prediction equation, and asecond group, the `validation` set, to be used to validate theprediction equation. There are a number of ways to select the samplesfor each set. In this example the samples were ranked according to eachof the characters that were to be predicted and every other sample wasselected for the calibration set (33 samples) and the validation set (32samples). Thus, for each character that was evaluated, a differentselection was made from the 65 samples to establish the respectivecalibration and validation sample sets.

The ranges, mean, median and variation in the laboratory-determinedvalues for each of the characters of interest in the calibration andvalidation sets are listed in Table 2.

The software for scanning, mathematical processing and statisticalanalysis were supplied with the spectrophotometer by the manufacturers.The spectral data were transformed by taking the second derivative ofthe logarithm of the inverse of the reflectance (R) at each wavelength(d" log (1/R)). The similarities amongst the spectra (FIG. 1) of thesamples in the validation and calibration sets were determined usingprincipal components scores to rank the spectra according to theMahalanobis distance from the average of the spectra. The Mahalanobisdistance values were standardized by dividing them by their averagevalue, and were denoted `global` H values (Table 3).

Calibration equations were developed using the calibration samples byregressing the data from the laboratory analyses of each biomechanicalproperty against the corresponding transformed spectral data using thefollowing mathematical methods:

a) Stepwise linear regression

b) Step-up linear regression

c) Principal components regression (PCR)

a) Partial least squares regression (PLS). and

e) Modified partial least squares regression (MPLS).

Stepwise calibrations were developed for each calibration set of samplesusing the mathematical treatments of the spectral data 2,2,2; 2,5,5;2,10,5; and 2,10,10; where the first number denotes that the secondderivative was used, the second indicates that second derivatives of thespectral data (determined at 2 nm intervals) were taken at intervals of4, 10 or 20 nm, and the third indicates that the function was smoothedusing the `boxcar` method over intervals of wavelength of 4, 10, or 20nm (Table 4a). Likewise step-up calibrations were developed for eachcalibration set with up to 6 terms in each calibration equation usingmathematical treatments 2,2,2; 2,5,5; 2,10,5; and 2,10,10 (Table 4b).Calibrations developed for each calibration set using principalcomponents regression, partial least squares regression, or modifiedpartial least squares regression each were developed using mathematicaltreatments 2,5,5 and 25 2,10,10 (Table 4c).

In developing the calibration equations in the stepwise and step-upregressions, only wavelengths with partial F-statistic of more than 8were accepted for the models.

For each calibration using each calibration set the followingcalibration statistics were determined:

a) Squared multiple correlation coefficient (R²), an indication of theproportion of the variation in the calibration set that is adequatelymodelled by the calibration equation.

b) The standard error of calibration (SEC) together with its confidenceinterval (±CL), which is the standard deviation for the residuals due todifference between the laboratory determined (reference) and the NIRpredicted values for samples within the calibration set

Once the calibration equations were developed, each equation wasvalidated by using it to predict the respective biomechanical propertyvalues for each sample in the validation sample set. For eachcalibration equation the following validation statistics weredetermined:

a) Simple linear correlation coefficient (r²) between the laboratorydetermined and NIR predicted values.

b) The bias (or systematic error) in the regression relationship betweenthe laboratory determined (reference) and NIR predicted values.

c) The confidence limits of the bias in the regression relationshipbetween the laboratory determined (reference) and NIR predicted values.

d) The standard error of prediction, corrected for bias (SEP(C)), whichrepresents the unexplained error of the prediction, the deviation of thedifferences between laboratory determined and NIR predicted values.

e) The coefficient of determination, or slope (β), and y-intercept (α)of the linear regression relationship between the laboratory determinedand NIR predicted values.

f) The residual standard deviation (RSD) of the linear regressionrelationship between the laboratory determined and NIR predicted values.

In addition, the calibration equations were validated using a proceduresof cross-validation. These are procedures where every sample in thecalibration set was used once for prediction, and the standard error ofvalidation corrected for bias (SEV(C), for stepwise and step-upregressions) and cross-validation (SECV, for multivariate regressions)can be determined.

Calibration equations for each biomechanical character were selectedusing the following criteria:

a) Lowest partial F-ratio, highest R², lowest SEC and, for PCR, PLS andMPLS, lowest SEV(C) (or, for multivariate regressions, SECV)

b) Highest r², lowest bias and |bias|<bias confidence limit. lowestSEP(C), β closest to 1.0, α closest to 0, and lowest RSD. As well,SEP(C) was compared with the standard error of laboratory determinedvalues amongst all 65 samples, listed in Table 5.

Calibration equations were similarly established to predict in vivodigestibility and in vitro digestibility. The coefficients for eachwavelength in the selected calibration equations from stepwise orstep-up regression analyses are listed in Table 6a, and those frommultivariate analyses are listed in Table 6b.

Simple linear correlation coefficient (r²) between the laboratorydetermined and NIR predicted values for each of the biomechanicalcharacters (energies required to shear, comminute or compress) anddigestibility of dry matter determined in vivo or in vitro of thesamples in the validation set are shown in FIGS. 2a-2e, 3a-3e, and4a-4e. NIR predicted values are predicted using calibration equationsthat best met the criteria listed above.

Example B Prediction of FCC and VFC Using NIR Determinations of EnergyRequired to Shear and In Vivo Digestibility

To demonstrate the prediction of voluntary feed consumption using NIRdetermined values for a biomechanical character and digestibility offorages, samples of Panicum spp. hay were selected which were common toboth of the validation sample sets used to establish the NIR predictionequations for energy required to shear and in viva digestibility. Thehays represented the range of varieties in the sample set, and arelisted in Table 7. The samples were scanned by the samespectrophotometer that was used to establish the calibration equations,and the absorption spectra were recorded in the range 1100 to 2500 nm at2 nm intervals. Values for energy required to shear and in vivodigestibility were predicted from calibration equations (Tables 4a 4band 4c) using the recorded spectra data.

These values then were used to estimate FCC from the relationshipbetween biomechanical character(s) and FCC of the range of forages usedby Weston and Davis (1991). Energy required to shear the forages used byWeston and Davis was determined according to Baker et al. (1993). Therelationship between the energy required to shear these forages (kJ/m²)and FCC (g organic matter (OM)/d/kg metabolic body weight (MBW)) wasdescribed by the relationship:

    Energy required to shear (x)=-26.13+5.53(FCC(y))

where R=0.92; RSD=8.70; N=13; P<0.0001.

FCC from this relationship and in vivo digestibility predicted by NIRwere then used to estimate VFC, as the difference between the animal'scapacity to use energy (as defined by Weston and Davis, 1991) and FCC.These data are summarised in Table 8.

VFC predicted in this way explained most of the variation in actual VFC(R=0.87; RSD=5.04; P=0.023) (FIG. 5).

                                      TABLE 1                                     __________________________________________________________________________    Description of herbage used in this example.                                                            Part of                                                                           Process                                         Genus                                                                              Species                                                                              Variety                                                                             Common name                                                                           plant                                                                             undergone                                                                             Stage of maturity                                                                            Regrowth                 __________________________________________________________________________    Panicum                                                                            coloratum                                                                            Bambatal                                                                            Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom (9 weeks' regrowth)                                                               late bloom -                                                                  regrowth                 Panicum                                                                            coloratum                                                                            Bambatal                                                                            Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom (13 weeks' regrowth)                                                              late bloom -                                                                  regrowth                 Panicum                                                                            coloratum                                                                            Bambatal                                                                            Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom (4 weeks' regrowth)                                                               late bllom -                                                                  regrowth                 Panicum                                                                            coloratum                                                                            Bambatal                                                                            Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom (1 month's                                                                         mid bloom -regrowth      Panicum                                                                            coloratum                                                                            Bambatal                                                                            Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom (10 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                 Panicum                                                                            coloratum                                                                            Bambatal                                                                            Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom (6 weeks' regrowth)                                                                mid bloom -                                                                   regrowth                 Panicum                                                                            coloratum                                                                            Bambatal                                                                            Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     vegetative regrowth (29                                                                      vegetative regrowth      Panicum                                                                            coloratum                                                                            Kabulabula                                                                          Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom     late bloom                           CPI 16796                                                         Panicum                                                                            coloratum                                                                            Kabulabula                                                                          Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom (4 weeks' regrowth)                                                               late bloom -                                                                  regrowth                             CPI 16796                                                         Panicum                                                                            coloratum                                                                            Kabulabula                                                                          Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom (19 weeks' regrowth)                                                              late bloom -                                                                  regrowth                             CPI 16796                                                         Panicum                                                                            coloratum                                                                            Kabulabula                                                                          Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom (14 weeks' regrowth)                                                              late bloom -                                                                  regrowth                             CPI 16796                                                         Panicum                                                                            coloratum                                                                            Kabulabula                                                                          Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom 9 weeks' regrowth)                                                                 mid bloom -                                                                   regrowth                             CPI 16796                                                         Panicum                                                                            coloratum                                                                            Kabulabula                                                                          Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom 6 weeks' regrowth)                                                                 mid bloom -                                                                   regrowth                             CPI 16796                                                         Panicum                                                                            coloratum                                                                            Kabulabula                                                                          Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     vegetative regrowth (28                                                                      vegetative regrowth                  CPI 16796                                                         Panicum                                                                            coloratum var                                                                        Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     early bloom (1 month's                                                                       late bloom -                                                                  regrowth                      Makarikariense                                                           Panicum                                                                            coloratum var                                                                        Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom (14 weeks                                                                         late bloom -                                                                  regrowth                      Makarikariense                                                           Panicum                                                                            coloratum var                                                                        Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     late bloom (4 weeks' regrowth)                                                               late bloom -                                                                  regrowth                      Makarikariense                                                           Panicum                                                                            coloratum var                                                                        Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom (8 weeks' regrowth)                                                                mid bloom -                                                                   regrowth                      Makarikariense                                                           Panicum                                                                            coloratum var                                                                        Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom (10 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                      Makarikariense                                                           Panicum                                                                            coloratum var                                                                        Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     vegetative regrowth (31                                                                      vegetative regrowth           Makarikariense                                                           Panicum                                                                            coloratum var                                                                        Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom (1 month's                                                                         mid bloom -                                                                   regrowth                      Makarikariense                                                           Panicum                                                                            coloratum var                                                                        Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                     mid bloom (4 weeks' regrowth)                                                                mid bloom -                                                                   regrowth                      Makarikariense                                                           Panicum                                                                            maximum                                                                              Coloniso                                                                            Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     late bloom (4 weeks' regrowth)                                                               late bloom -                                                                  regrowth                 Panicum                                                                            maximum                                                                              Coloniso                                                                            Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     mid bloom (13 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                 Panicum                                                                            maximum                                                                              Coloniso                                                                            Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     mid bloom (10 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                 Panicum                                                                            maximum                                                                              Coloniso                                                                            Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     vegetative regrowth (4                                                                       vegetative regrowth      Panicum                                                                            maximum                                                                              Coloniso                                                                            Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     vegetative regrowth (33                                                                      vegetative regrowth      Panicum                                                                            maximum                                                                              Coloniso                                                                            Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     vegetative regrowth (28                                                                      vegetative regrowth      Panicum                                                                            maximum                                                                              Coloniso                                                                            Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     vegetative regrowth (1                                                                       vegetative regrowth      Panicum                                                                            maximum                                                                              Coloniso                                                                            Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     vegetative regrowth (6                                                                       vegetative regrowth      Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     early bloom (1 month's                                                                       early bloom                                                                   -regrowth                Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     early bloom (10 weeks' regrowth)                                                             early bloom -                                                                 regrowth                 Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     late bloom (4 weeks' regrowth)                                                               late bloom -                                                                  regrowth                 Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     mid bloom (13 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                 Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          leaf                                                                              dried and chaffed                                                                     54 days' regrowth                                                                            regrowth                 Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          leaf                                                                              dried and chaffed                                                                     75 days' regrowth                                                                            regrowth                 Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          leaf                                                                              dried and chaffed                                                                     68 days' regrowth                                                                            regrowth                 Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     vegetative (8 weeks' regrowth)                                                               vegetative               Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     vegetative regrowth (9                                                                       vbegetative                                                                   regrowth                 Panicum                                                                            maximum                                                                              Hamll Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                     vegetative regrowth (32                                                                      vegetative regrowth      Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     late bloom (6 weeks' regrowth)                                                               late bloom -                                                                  regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (1 month's                                                                         mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (10 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (14 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (4 weeks' regrowth)                                                                mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (15 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (9 weeks' regrowth)                                                                mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (1 month's)                                                                        mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (13 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (4 weeks' regrowth)                                                                mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     mid bloom (11 weeks' regrowth)                                                               mid bloom -                                                                   regrowth                      trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     vegetative regrowth (28                                                                      vegetative regrowth           trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     vegetative regrowth (32                                                                      vegetative regrowth           trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     vegetative regrowth (4                                                                       vegetative regrowth           trichoglume                                                              Panicum                                                                            maximum var.                                                                         Petrie                                                                              Green Panlo                                                                           aerial                                                                            dried and chaffed                                                                     vegetative regrowth (4                                                                       vegetative regrowth           trichoglume                                                              __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________    Summary statistics for each calibration and validation set                            Energy required                                                                       Energy required                                                                       Energy required                                                                       Digestibility of                                                                      Digestibility of dry                          to shear                                                                              to comminute                                                                          to compress                                                                           dry matter in vivo                                                                    matter in vitro                               (kJ/m.sup.2)                                                                          (kJ/kg DM)                                                                            (kJ/kg DM)                                                                            (%)     (%)                                   __________________________________________________________________________    Energy required to shear                                                      Calibration set                                                               mean    15.48   134.9   3.70    55.7    53.3                                  median  15.17   133.8   3.65    56.0    55.1                                  maximum 20.95   216.5   4.39    64.0    63.0                                  minimum 10.80   72.5    3.25    43.0    39.8                                  standard deviation                                                                    2.572   37.50   0.265   5.73    6.97                                  Validation set                                                                mean    15.43   130.9   3.78    55.6    52.7                                  median  15.20   128.3   3.75    56.5    53.3                                  maximum 20.43   205.2   4.24    64.0    63.0                                  minimum 10.94   54.5    3.34    47.0    40.1                                  standard deviation                                                                    2.444   37.50   0.229   5.36    7.01                                  Energy required to comminute                                                  Calibration set                                                               mean    15.01   133.1   3.69    55.7    52.8                                  median  14.76   129.5   3.70    57.0    54.7                                  maximum 19.97   216.5   4.18    64.0    63.0                                  minimum 10.80   54.5    3.25    43.0    39.8                                  standard deviation                                                                    2.444   38.82   0.227   5.64    7.06                                  Validation set                                                                mean    15.92   132.9   3.79    55.6    53.2                                  median  15.97   130.2   3.79    55.5    54.7                                  maximum 20.95   205.2   4.39    64.0    62.5                                  minimum 11.48   60.7    3.34    47.0    40.9                                  standard deviation                                                                    2.490   36.20   0.263   5.47    6.92                                  Energy required to compress                                                   Calibration set                                                               mean    15.28   128.1   3.74    56.3    53.8                                  median  15.07   128.4   3.72    57.0    54.7                                  maximum 19.97   204.0   4.39    64.0    63.0                                  minimum 10.80   54.5    3.25    47.0    39.8                                  standard deviation                                                                    2.477   38.00   0.261   5.15    6.64                                  Validation set                                                                mean    15.64   138.0   3.74    55.0    52.2                                  median  15.42   132.5   3.72    54.5    54.5                                  maximum 20.95   216.5   4.24    64.0    62.0                                  minimum 11.46   60.7    3.34    43.0    40.1                                  standard deviation                                                                    2.530   36.39   0.240   5.87    7.26                                  Digestibility of dry matter in vivo                                           Calibration set                                                               mean    15.14   133.9   3.74    55.5    53.1                                  median  15.17   128.4   3.72    56.0    55.1                                  maximum 20.95   216.5   4.24    64.0    63.0                                  minimum 10.80   60.7    3.25    43.0    40.1                                  standard deviation                                                                    2.528   36.39   0.247   5.73    7.33                                  Validation set                                                                mean    15.78   132.1   3.75    55.7    52.9                                  median  15.20   134.7   3.72    56.5    54.4                                  maximum 20.37   205.2   4.39    64.0    63.0                                  minimum 10.94   54.5    3.34    47.0    39.8                                  standard deviation                                                                    2.446   38.70   0.255   5.36    6.63                                  Digestibility of dry matter in vitro                                          Calibration set                                                               mean    14.70   131.3   3.75    55.6    53.0                                  median  14.34   129.3   3.71    56.0    54.7                                  maximum 19.36   216.5   4.39    64.0    63.0                                  minimum 10.80   54.5    3.25    43.0    40.1                                  standard deviation                                                                    2.235   42.58   0.241   5.78    6.94                                  Validation set                                                                mean    16.19   134.6   3.74    55.6    53.0                                  median  16.16   133.8   3.74    56.0    54.7                                  maximum 20.95   194.8   4.24    64.0    63.0                                  minimum 10.94   65.7    3.34    47.0    39.8                                  standard deviation                                                                    2.538   31.84   0.260   5.33    7.05                                  __________________________________________________________________________

                  TABLE 3                                                         ______________________________________                                        Mahalanobis distances                                                                         Mean  Median  Range                                           ______________________________________                                        For full sample set:                                                                            0.655   0.623   0.203-1.983                                 For calibration sets for:                                                     Energy required to shear                                                                        0.588   0.549   0.171-1.646                                 Energy required to comminute                                                                    0.718   0.676   0.350-1.553                                 Energy required to compress                                                                     0.757   0.760   0.188-1.440                                 Digestibility of dry matter in vivo                                                             0.673   0.634   0.389-1.547                                 Digestibility of dry matter in vitro                                                            0.645   0.574   0.185-1.178                                 ______________________________________                                    

                  TABLE 4a                                                        ______________________________________                                        Calibration and validation statistics                                         ______________________________________                                                   Stepwise Regression                                                           2,2,2  2,5,5    2,10,5   2,10,10                                   ______________________________________                                        Energy required to shear                                                      Lowest partial F-ratio                                                                     10.27    6.18     8.27   4.70                                    R.sup.2      0.798    0.787    0.795  0.780                                   SEC          1.155    1.188    1.166  1.207                                   SEC CL       1.493    1.535    1.507  1.560                                   SEV(C)       1.230    1.306    1.273  1.322                                   r.sup.2      0.368    0.625    0.520  0.495                                   Bias         0.690    0.710    0.700  0.720                                   Bias CL      1.484    1.527    1.498  1.551                                   SEP (C)      1.500    1.540    1.520  1.570                                   Slope        0.604    0.617    0.598  0.758                                   Intercept    6.340    5.440    5.640  3.710                                   R.S.D.       1.627    1.627    1.484  1.476                                   Bias CLne.Bias|                                                                   -0.794   0.817    0.798  0.831                                   |Bias| < Bias CL?                                                        Yes      Yes      Yes    Yes                                     number of terms                                                                            6        5        5      6                                       Energy required to comminute                                                  Lowest partial F-ratio                                                                     5.54     4.45     16.55  10.89                                   R.sup.2      0.910    0.802    0.818  0.831                                   SEC          11.626   17.281   16.546 15.980                                  SEC CL       1.493    1.535    1.507  1.560                                   SEV(C)       13.103   18.040   17.587 17.100                                  r.sup.2      0.363    0.429    0.374  0.213                                   Bias         6.980    10.370   9.930  9.590                                   Bias CL      14.941   22.209   21.264 20.537                                  SEP (C)      15.110   22.460   21.510 20.770                                  Slope        0.530    0.575    0.607  0.417                                   Intercept    58.300   48.900   48.600 74.600                                  R.S.D.       28.900   27.360   28.650 32.120                                  Bias CLne.Bias|                                                                   -7.961   -11.839  -11.334                                                                              -10.947                                 |Bias| < Bias CL?                                                        Yes      Yes      Yes    Yes                                     number of terms                                                                            6        3        4      4                                       Energy required to compress                                                   Lowest partial F-ratio                                                                     5.05     4.44     7.90   16.19                                   R.sup.2      0.784    0.500    0.525  0.534                                   SEC          0.121    0.209    0.204  0.202                                   SEC CL       1.493    1.535    1.507  1.560                                   SEV(C)       0.135    0.224    0.217  0.215                                   r.sup.2      0.069    0.113    0.008  0.067                                   Bias         0.070    0.130    0.120  0.120                                   Bias CL      0.156    0.269    0.262  0.260                                   SEP (C)      0.160    0.270    0.270  0.260                                   Slope        0.180    -0.080   0.314  0.211                                   Intercept    3.060    4.030    2.580  2.960                                   R.S.D.       0.229    0.229    0.227  0.232                                   Bias CLne.Bias|                                                                   -0.086   -0.139   -0.142 -0.140                                  |Bias| < Bias CL?                                                        Yes      Yes      Yes    Yes                                     number of terms                                                                            6        4        4      4                                       Digestibility of dry matter in vivo                                           Lowest partial F-ratio                                                                     7.63     20.68    4.28   6.08                                    R.sup.2      0.934    0.917    0.914  0.921                                   SEC          1.107    1.236    1.258  1.207                                   SEC CL       1.493    1.535    1.507  1.560                                   SEV(C)       1.215    1.368    1.341  1.284                                   r.sup.2      0.654    0.881    0.878  0.876                                   Bias         1.070    0.890    0.910  0.900                                   Bias CL      0.156    0.269    0.262  0.260                                   SEP (C)      2.320    1.940    1.980  1.960                                   Slope        0.705    0.878    0.840  0.827                                   Intercept    16.500   6.690    8.640  9.340                                   R.S.D.       3.153    1.852    1.873  1.888                                   Bias CLne.Bias|                                                                   0.914    0.621    0.648  0.640                                   |Bias| < Bias CL?                                                        No       No       No     No                                      number of terms                                                                            6        6        6      5                                       ______________________________________                                                   Stepwise Regression                                                           2,2,2,1                                                                              2,5,5    2,10,5   2,10,10                                   ______________________________________                                        Digestibility of dry matter in vitro                                          Lowest partial F-ratio                                                                     7.68     11.84    4.33   6.31                                    R.sup.2      0.935    0.933    0.915  0.922                                   SEC          1.808    1.751    2.052  1.974                                   SEC CL       1.493    1.535    1.507  1.560                                   SEV(C)       1.984    1.981    2.186  2.100                                   r.sup.2      0.699    0.847    0.743  0.736                                   Bias         1.080    1.050    1.230  1.180                                   Bias CL      2.324    2.250    2.637  2.537                                   SEP (C)      2.340    2.280    2.670  2.570                                   Slope        0.839    0.962    0.775  0.763                                   Intercept    8.790    1.650    12.200 12.700                                  R.S.D.       3.805    3.794    3.805  2.719                                   Bias CLne.Bias|                                                                   -1.244   -1.200   -1.407 -1.357                                  |Bias| < Bias CL?                                                        Yes      Yes      Yes    Yes                                     number of terms                                                                            6        5        6      5                                       ______________________________________                                    

                                      TABLE 4b                                    __________________________________________________________________________    Calibration and validation statistics (Step-up regression)                    __________________________________________________________________________              Step-up Regression 2, 2, 2                                                                            Step-up Regression 2, 5, 5                            1 term                                                                            2 terms                                                                           3 terms                                                                           4 terms                                                                           5 terms                                                                           6 terms                                                                           1 term                                                                            2 terms                                                                           3 terms                                                                           4 terms                                                                           5 terms                                                                           6                       __________________________________________________________________________                                                          terms                   Energy required to shear                                                      Lowest partial F-ratio                                                                  29.33                                                                             13.83                                                                             6.65                                                                              5.29                                                                              5.89                                                                              3.23                                                                              25.70                                                                             21.99                                                                             5.71                                                                              1.60                                                                              4.92                                                                              1.70                    R.sup.2   0.470                                                                             0.625                                                                             0.684                                                                             0.725                                                                             0.766                                                                             0.784                                                                             0.436                                                                             0.663                                                                             0.709                                                                             0.715                                                                             0.778                                                                             0.792                   SEC       1.873                                                                             1.575                                                                             1.445                                                                             1.349                                                                             1.244                                                                             1.196                                                                             1.932                                                                             1.492                                                                             1.387                                                                             1.373                                                                             1.211                                                                             1.173                   SEC CL    2.420                                                                             2.035                                                                             1.867                                                                             1.743                                                                             1.608                                                                             1.546                                                                             2.497                                                                             1.928                                                                             1.792                                                                             1.774                                                                             1.565                                                                             1.516                   SEV (C)   1.973                                                                             1.672                                                                             1.561                                                                             1.476                                                                             1.390                                                                             1.318                                                                             2.022                                                                             1.571                                                                             1.476                                                                             1.470                                                                             1.357                                                                             1.319                   r.sup.2   0.371                                                                             0.344                                                                             0.310                                                                             0.205                                                                             0.202                                                                             0.168                                                                             0.375                                                                             0.531                                                                             0.557                                                                             0.557                                                                             0.631                                                                             0.635                   Bias      1.120                                                                             0.950                                                                             0.870                                                                             0.810                                                                             0.775                                                                             0.720                                                                             1.160                                                                             0.900                                                                             0.830                                                                             0.820                                                                             0.730                                                                             0.700                   Bias CL   2.407                                                                             2.024                                                                             1.857                                                                             1.734                                                                             1.599                                                                             1.537                                                                             2.483                                                                             1.917                                                                             1.783                                                                             1.765                                                                             1.556                                                                             1.507                   SEP (C)   2.430                                                                             2.050                                                                             1.880                                                                             1.750                                                                             1.620                                                                             1.550                                                                             2.510                                                                             1.940                                                                             1.800                                                                             1.780                                                                             1.570                                                                             1.520                   Slope     1.000                                                                             0.795                                                                             0.784                                                                             0.598                                                                             0.549                                                                             0.498                                                                             0.643                                                                             0.606                                                                             0.616                                                                             0.633                                                                             0.644                                                                             0.633                   Intercept -0.120                                                                            3.030                                                                             3.290                                                                             6.090                                                                             6.950                                                                             7.790                                                                             6.390                                                                             5.790                                                                             5.560                                                                             5.270                                                                             5.050                                                                             5.170                   R.S.D.    1.896                                                                             1.803                                                                             1.773                                                                             1.769                                                                             1.732                                                                             2.058                                                                             1.891                                                                             1.806                                                                             1.698                                                                             1.656                                                                             2.317                                                                             1.945                   |Bias| - Bias CL                                                      -1.287                                                                            -1.074                                                                            -0.987                                                                            -0.924                                                                            -0.824                                                                            -0.817                                                                            -1.323                                                                            -1.017                                                                            -0.953                                                                            -0.945                                                                            -0.826                                                                            -0.807                  |Bias| < Bias CL?                                                     Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes                     Energy required to comminute                                                  Lowest partial F-ratio                                                                  81.33                                                                             12.82                                                                             9.62                                                                              6.10                                                                              6.71                                                                              2.92                                                                              67.30                                                                             8.96                                                                              2.73                                                                              4.91                                                                              5.06                                                                              4.26                    R.sup.2   0.715                                                                             0.794                                                                             0.840                                                                             0.864                                                                             0.887                                                                             0.894                                                                             0.974                                                                             0.741                                                                             0.755                                                                             0.782                                                                             0.810                                                                             0.830                   SEC       20.719                                                                            17.829                                                                            15.538                                                                            14.330                                                                            13.061                                                                            12.620                                                                            22.149                                                                            19.757                                                                            19.213                                                                            18.105                                                                            16.921                                                                            15.983                  SEC CL    2.420                                                                             2.035                                                                             1.867                                                                             1.743                                                                             1.608                                                                             1.546                                                                             2.497                                                                             1.928                                                                             1.792                                                                             1.774                                                                             1.565                                                                             1.516                   SEV (C)   21.511                                                                            18.353                                                                            16.378                                                                            15.230                                                                            13.967                                                                            13.633                                                                            22.769                                                                            20.547                                                                            20.096                                                                            19.092                                                                            18.262                                                                            17.484                  r.sup.2   0.322                                                                             0.424                                                                             0.421                                                                             0.411                                                                             0.371                                                                             0.373                                                                             0.183                                                                             0.199                                                                             0.148                                                                             0.099                                                                             0.114                                                                             0.098                   Bias      12.430                                                                            10.580                                                                            9.320                                                                             8.600                                                                             7.840                                                                             7.570                                                                             13.290                                                                            11.850                                                                            11.530                                                                            10.860                                                                            10.150                                                                            9.590                   Bias CL   26.627                                                                            22.656                                                                            19.969                                                                            18.416                                                                            16.785                                                                            16.219                                                                            28.465                                                                            25.391                                                                            24.692                                                                            23.268                                                                            21.746                                                                            20.541                  SEP (C)   26.940                                                                            22.920                                                                            20.200                                                                            18.630                                                                            16.980                                                                            16.410                                                                            28.790                                                                            25.680                                                                            24.980                                                                            23.540                                                                            22.000                                                                            20.780                  Slope     0.605                                                                             0.623                                                                             0.577                                                                             0.560                                                                             0.524                                                                             0.521                                                                             0.491                                                                             0.518                                                                             0.441                                                                             0.346                                                                             0.365                                                                             0.317                   Intercept 47.100                                                                            43.900                                                                            48.900                                                                            52.900                                                                            58.300                                                                            57.800                                                                            60.100                                                                            58.500                                                                            70.800                                                                            84.600                                                                            82.700                                                                            89.600                  R.S.D.    29.810                                                                            27.480                                                                            27.550                                                                            27.790                                                                            28.720                                                                            28.670                                                                            32.720                                                                            32.400                                                                            33.420                                                                            34.370                                                                            34.070                                                                            34.380                  |Bias| - Bias CL                                                      -14.197                                                                           -12.076                                                                           -9.816                                                                            -8.945                                                                            -8.649                                                                            -15.175                                                                           -13.541                                                                           -13.162                                                                           -12.408                                                                           -11.596                                                                           -10.951                     |Bias| < Bias CL?                                                     Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes                     Energy required to compress                                                   Lowest partial F-ratio                                                                  7.28                                                                              6.24                                                                              3.22                                                                              2.65                                                                              3.10                                                                              0.00                                                                              8.07                                                                              4.23                                                                              4.08                                                                              2.21                                                                              5.36                                                                              1.87                    R.sup.2   0.164                                                                             0.285                                                                             0.334                                                                             0.370                                                                             0.440                                                                             0.530                                                                             0.181                                                                             0.258                                                                             0.327                                                                             0.445                                                                             0.520                                                                             0.535                   SEC       0.270                                                                             0.250                                                                             0.241                                                                             0.235                                                                             0.221                                                                             0.203                                                                             0.268                                                                             0.255                                                                             0.243                                                                             0.220                                                                             0.205                                                                             0.202                   SEC CL    2.420                                                                             2.035                                                                             1.867                                                                             1.743                                                                             1.608                                                                             1.546                                                                             2.497                                                                             1.928                                                                             1.792                                                                             1.774                                                                             1.565                                                                             1.518                   SEV (C)   0.277                                                                             0.259                                                                             0.252                                                                             0.248                                                                             0.238                                                                             0.226                                                                             0.276                                                                             0.268                                                                             0.257                                                                             0.241                                                                             0.227                                                                             0.222                   r.sup.2   0.067                                                                             0.089                                                                             0.087                                                                             0.104                                                                             0.067                                                                             0.033                                                                             0.039                                                                             0.064                                                                             0.038                                                                             0.005                                                                             0.010                                                                             0.006                   Bias      0.160                                                                             0.150                                                                             0.140                                                                             0.140                                                                             0.130                                                                             0.120                                                                             0.160                                                                             0.150                                                                             0.150                                                                             0.130                                                                             0.120                                                                             0.120                   Bias CL   0.347                                                                             0.321                                                                             0.310                                                                             0.302                                                                             0.284                                                                             0.261                                                                             0.344                                                                             0.328                                                                             0.312                                                                             0.283                                                                             0.263                                                                             0.260                   SEP (C)   0.350                                                                             0.330                                                                             0.310                                                                             0.310                                                                             0.290                                                                             0.260                                                                             0.350                                                                             0.330                                                                             0.320                                                                             0.290                                                                             0.270                                                                             0.260                   Slope     0.367                                                                             0.394                                                                             0.345                                                                             0.341                                                                             0.280                                                                             0.156                                                                             0.267                                                                             0.295                                                                             0.198                                                                             0.068                                                                             0.085                                                                             0.063                   Intercept 2.380                                                                             2.270                                                                             2.460                                                                             2.470                                                                             2.690                                                                             3.160                                                                             2.750                                                                             2.640                                                                             3.010                                                                             3.490                                                                             3.420                                                                             3.510                   R.S.D.    0.235                                                                             0.232                                                                             0.235                                                                             0.239                                                                             0.239                                                                             0.239                                                                             0.236                                                                             0.233                                                                             0.230                                                                             0.229                                                                             0.233                                                                             0.239                   |Bias| - Bias CL                                                      -0.187                                                                            -0.171                                                                            -0.170                                                                            -0.162                                                                            -0.154                                                                            -0.141                                                                            -0.184                                                                            -0.178                                                                            -0.162                                                                            -0.153                                                                            -0.143                                                                            -0.140                  |Bias| < Bias CL?                                                     Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes                     Digestibility of dry matter in vivo                                           Lowest partial F-ratio                                                                  72.42                                                                             5.79                                                                              8.71                                                                              16.80                                                                             13.18                                                                             2.86                                                                              80.75                                                                             12.35                                                                             8.41                                                                              7.34                                                                              6.03                                                                              3.72                    R.sup.2   0.616                                                                             0.714                                                                             0.830                                                                             0.862                                                                             0.883                                                                             0.906                                                                             0.679                                                                             0.826                                                                             0.897                                                                             0.909                                                                             0.919                                                                             0.924                   SEC       3.555                                                                             -3.069                                                                            2.365                                                                             2.127                                                                             1.962                                                                             1.755                                                                             3.248                                                                             2.394                                                                             1.840                                                                             1.728                                                                             1.635                                                                             1.588                   SEC CL    2.420                                                                             2.035                                                                             1.867                                                                             1.743                                                                             1.608                                                                             1.546                                                                             2.497                                                                             1.928                                                                             1.792                                                                             1.774                                                                             1.565                                                                             1.516                   SEV (C)   3.666                                                                             3.250                                                                             2.447                                                                             2.312                                                                             2.152                                                                             1.956                                                                             3.328                                                                             2.457                                                                             1.972                                                                             1.884                                                                             1.828                                                                             1.782                   r.sup.2   0.785                                                                             0.712                                                                             0.684                                                                             0.787                                                                             0.884                                                                             0.768                                                                             0.755                                                                             0.740                                                                             0.884                                                                             0.893                                                                             0.876                                                                             0.869                   Bias      2.130                                                                             1.840                                                                             1.420                                                                             1.280                                                                             1.180                                                                             1.050                                                                             1.950                                                                             1.440                                                                             1.100                                                                             1.040                                                                             0.980                                                                             0.950                   Bias CL   0.347                                                                             0.321                                                                             0.310                                                                             0.302                                                                             0.284                                                                             0.261                                                                             0.344                                                                             0.328                                                                             0.312                                                                             0.283                                                                             0.263                                                                             0.260                   SEP (C)   4.620                                                                             3.990                                                                             3.070                                                                             2.770                                                                             2.550                                                                             2.280                                                                             4.220                                                                             3.110                                                                             2.390                                                                             2.250                                                                             2.130                                                                             2.060                   Slope     1.050                                                                             0.805                                                                             0.792                                                                             0.826                                                                             0.777                                                                             0.731                                                                             1.090                                                                             1.050                                                                             0.889                                                                             0.880                                                                             0.866                                                                             0.885                   Intercept -2.180                                                                            10.300                                                                            11.000                                                                            9.040                                                                             11.900                                                                            14.900                                                                            -5.290                                                                            -3.300                                                                            5.850                                                                             6.430                                                                             7.210                                                                             6.080                   R.S.D.    2.484                                                                             2.877                                                                             2.584                                                                             2.652                                                                             2.734                                                                             3.108                                                                             2.476                                                                             1.825                                                                             1.825                                                                             1.750                                                                             1.884                                                                             1.940                   |Bias| - Bias CL                                                      1.783                                                                             1.519                                                                             1.110                                                                             0.978                                                                             0.896                                                                             0.789                                                                             1.606                                                                             1.112                                                                             0.788                                                                             0.757                                                                             0.717                                                                             0.690                   |Bias| < Bias CL?                                                     No  No  No  No  No  No  No  No  No  No  No  No                      Digestibility of dry matter in vitro                                          Lowest partial F-ratio                                                                  73.30                                                                             5.73                                                                              8.71                                                                              17.00                                                                             13.23                                                                             2.99                                                                              81.21                                                                             12.38                                                                             8.48                                                                              7.23                                                                              6.07                                                                              3.72                    R.sup.2   0.692                                                                             0.733                                                                             0.788                                                                             0.905                                                                             0.915                                                                             0.715                                                                             0.791                                                                             0.833                                                                             0.863                                                                             0.884                                                                             0.894                       SEC       3.913                                                                             3.645                                                                             2.251                                                                             2.610                                                                             2.177                                                                             2.058                                                                             3.768                                                                             3.222                                                                             2.883                                                                             2.818                                                                             2.407                                                                             2.294                   SEC CL    2.420                                                                             2.035                                                                             1.867                                                                             1.743                                                                             1.608                                                                             1.546                                                                             2.497                                                                             1.928                                                                             1.792                                                                             1.774                                                                             1.565                                                                             1.516                   SEV (C)   4.020                                                                             3.186                                                                             3.411                                                                             2.a781                                                                            2.324                                                                             2.203                                                                             3.855                                                                             3.360                                                                             3.063                                                                             2.809                                                                             2.615                                                                             2.490                   r.sup.2   0.731                                                                             0.694                                                                             0.687                                                                             0.644                                                                             0.685                                                                             0.671                                                                             0.735                                                                             0.856                                                                             0.845                                                                             0.849                                                                             0.801                                                                             0.800                   Bias      2.350                                                                             2.190                                                                             1.950                                                                             1.570                                                                             1.310                                                                             1.230                                                                             2.260                                                                             1.930                                                                             1.730                                                                             1.570                                                                             1.440                                                                             1.380                   Bias CL   5.029                                                                             4.684                                                                             2.893                                                                             3.354                                                                             2.798                                                                             2.645                                                                             4.842                                                                             4.141                                                                             3.705                                                                             3.362                                                                             3.093                                                                             2.948                   SEP (C)   5.090                                                                             4.740                                                                             4.230                                                                             3.390                                                                             2.830                                                                             2.680                                                                             4.900                                                                             4.190                                                                             3.750                                                                             3.400                                                                             3.130                                                                             2.980                   Slope     0.946                                                                             0.868                                                                             0.861                                                                             0.877                                                                             0.860                                                                             0.830                                                                             1.080                                                                             0.994                                                                             1.020                                                                             0.976                                                                             0.975                                                                             0.914                   Intercept 2.000                                                                             5.890                                                                             6.550                                                                             6.140                                                                             7.240                                                                             9.150                                                                             -4.700                                                                            -0.410                                                                            -1.970                                                                            0.240                                                                             0.240                                                                             4.040                   R.S.D.    3.565                                                                             3.601                                                                             3.842                                                                             3.882                                                                             4.143                                                                             3.895                                                                             3.576                                                                             2.637                                                                             2.733                                                                             2.694                                                                             3.097                                                                             3.103                   |Bias| - Bias CL                                                      -2.879                                                                            -2.494                                                                            -0.943                                                                            -1.784                                                                            -1.488                                                                            -1.415                                                                            -2.582                                                                            -2.211                                                                            -1.975                                                                            -1.792                                                                            -1.653                                                                            -1.568                  |Bias| < Bias CL?                                                     Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes                     __________________________________________________________________________              Step-up Regression 2,10,5                                                                             Step-up Regression 2, 10, 10                          1 term                                                                            2 terms                                                                           3 terms                                                                           4 terms                                                                           5 terms                                                                           6 terms                                                                           1 term                                                                            2 terms                                                                           3 terms                                                                           4 terms                                                                           5 terms                                                                           6                       __________________________________________________________________________                                                          terms                   Energy required to shear                                                      Lowest partial F-ratio                                                                  25.11                                                                             14.92                                                                             5.87                                                                              4.42                                                                              7.81                                                                              1.89                                                                              23.54                                                                             15.23                                                                             4.01                                                                              4.30                                                                              4.35                                                                              4.66                    R.sup.2   0.430                                                                             0.606                                                                             0.661                                                                             0.697                                                                             0.755                                                                             0.763                                                                             0.413                                                                             0.598                                                                             0.641                                                                             0.678                                                                             0.721                                                                             0.755                   SEC       1.942                                                                             1.613                                                                             1.496                                                                             1.415                                                                             1.273                                                                             1.252                                                                             1.970                                                                             1.631                                                                             1.541                                                                             1.460                                                                             1.358                                                                             1.274                   SEC CL    2.510                                                                             2.084                                                                             1.933                                                                             1.829                                                                             1.645                                                                             1.618                                                                             2.546                                                                             2.108                                                                             1.991                                                                             1.887                                                                             1.755                                                                             1.646                   SEV (C)   2.020                                                                             1.674                                                                             1.611                                                                             1.541                                                                             1.403                                                                             1.392                                                                             2.047                                                                             1.689                                                                             1.612                                                                             1.569                                                                             1.494                                                                             1.411                   r.sup.2   0.273                                                                             0.398                                                                             0.456                                                                             0.473                                                                             0.476                                                                             0.498                                                                             0.291                                                                             0.333                                                                             0.401                                                                             0.454                                                                             0.517                                                                             0.541                   Bias      1.170                                                                             0.970                                                                             0.900                                                                             0.850                                                                             0.760                                                                             0.750                                                                             1.180                                                                             0.980                                                                             0.920                                                                             0.880                                                                             0.810                                                                             0.760                   Bias CL   2.496                                                                             2.073                                                                             1.923                                                                             1.818                                                                             1.636                                                                             1.609                                                                             2.532                                                                             2.096                                                                             1.980                                                                             1.876                                                                             1.745                                                                             1.637                   SEP (C)   2.520                                                                             2.100                                                                             1.950                                                                             1.840                                                                             1.650                                                                             1.630                                                                             2.560                                                                             2.120                                                                             2.000                                                                             1.900                                                                             1.760                                                                             1.660                   Slope     0.706                                                                             0.723                                                                             0.717                                                                             0.707                                                                             0.610                                                                             0.616                                                                             0.737                                                                             0.581                                                                             0.639                                                                             0.653                                                                             0.715                                                                             0.709                   Intercept 4.150                                                                             3.950                                                                             4.320                                                                             4.260                                                                             5.620                                                                             5.440                                                                             3.720                                                                             5.850                                                                             5.040                                                                             5.040                                                                             4.130                                                                             4.160                   R.S.D.    2.170                                                                             2.193                                                                             2.343                                                                             2.367                                                                             2.524                                                                             2.375                                                                             2.179                                                                             1.607                                                                             1.666                                                                             1.644                                                                             1.889                                                                             1.893                   |Bias| - Bias CL                                                      -1.326                                                                            -1.103                                                                            -1.023                                                                            -0.968                                                                            -0.876                                                                            -0.859                                                                            -1.352                                                                            -1.116                                                                            -1.060                                                                            -0.996                                                                            -0.935                                                                            -0.877                  |Bias| < Bias CL?                                                     Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes                     Energy required to comminute                                                  Lowest partial F-ratio                                                                  76.72                                                                             5.31                                                                              2.76                                                                              2.18                                                                              1.68                                                                              1.01                                                                              74.65                                                                             5.39                                                                              2.13                                                                              2.96                                                                              4.38                                                                              1.49                    R.sup.2   0.730                                                                             0.739                                                                             0.754                                                                             0.763                                                                             0.772                                                                             0.800                                                                             0.698                                                                             0.735                                                                             0.745                                                                             0.781                                                                             0.787                                                                             0.791                   SEC       21.158                                                                            19.825                                                                            19.267                                                                            18.887                                                                            18.518                                                                            17.344                                                                            21.345                                                                            19.977                                                                            19.611                                                                            18.982                                                                            17.929                                                                            17.768                  SEC CL    2.510                                                                             2.084                                                                             1.933                                                                             1.829                                                                             1.645                                                                             1.618                                                                             2.548                                                                             2.108                                                                             1.991                                                                             1.887                                                                             1.755                                                                             1.646                   SEV (C)   21.803                                                                            20.707                                                                            20.279                                                                            19.690                                                                            19.499                                                                            18.691                                                                            22.033                                                                            20.904                                                                            20.985                                                                            19.911                                                                            18.777                                                                            18.634                  r.sup.2   0.460                                                                             0.468                                                                             0.414                                                                             0.394                                                                             0.330                                                                             0.215                                                                             0.434                                                                             0.450                                                                             0.408                                                                             0.397                                                                             0.357                                                                             0.387                   Bias      12.690                                                                            11.890                                                                            11.560                                                                            11.330                                                                            11.110                                                                            10.410                                                                            12.810                                                                            11.990                                                                            11.700                                                                            11.390                                                                            10.760                                                                            10.660                  Bias CL   27.191                                                                            25.478                                                                            24.761                                                                            24.273                                                                            23.799                                                                            22.290                                                                            27.432                                                                            25.674                                                                            25.203                                                                            24.395                                                                            23.042                                                                            22.835                  SEP (C)   27.510                                                                            25.770                                                                            25.050                                                                            24.550                                                                            24.070                                                                            22.550                                                                            27.750                                                                            25.970                                                                            25.490                                                                            24.680                                                                            23.310                                                                            23.100                  Slope     0.793                                                                             0.737                                                                             0.688                                                                             0.649                                                                             0.598                                                                             0.468                                                                             0.776                                                                             0.729                                                                             0.694                                                                             0.645                                                                             0.622                                                                             0.633                   Intercept 18.300                                                                            24.500                                                                            31.800                                                                            39.600                                                                            48.100                                                                            67.100                                                                            20.200                                                                            25.600                                                                            30.800                                                                            39.000                                                                            43.600                                                                            42.200                  R.S.D.    26.610                                                                            26.420                                                                            27.720                                                                            28.170                                                                            29.640                                                                            32.080                                                                            27.230                                                                            26.850                                                                            27.860                                                                            28.100                                                                            29.030                                                                            28.350                  |Bias| - Bias CL                                                      -14.501                                                                           -13.588                                                                           -13.201                                                                           -12.943                                                                           -12.689                                                                           -11880                                                                            -14.622                                                                           -13.684                                                                           -13.503                                                                           -13.005                                                                           -12.282                                                                           -12.175                 |Bias| < Bias CL?                                                     Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes                     Energy required to compress                                                   Lowest partial F-ratio                                                                  8.16                                                                              2.24                                                                              8.06                                                                              4.06                                                                              1.97                                                                              4.98                                                                              6.50                                                                              4.94                                                                              4.91                                                                              1.75                                                                              3.54                                                                              3.83                    R.sup.2   0.183                                                                             0.214                                                                             0.364                                                                             0.457                                                                             0.532                                                                             0.592                                                                             0.147                                                                             0.243                                                                             0.397                                                                             0.412                                                                             0.461                                                                             0.512                   SEC       0.267                                                                             0.262                                                                             0.236                                                                             0.218                                                                             0.202                                                                             0.189                                                                             0.273                                                                             0.257                                                                             0.230                                                                             0.227                                                                             0.217                                                                             0.207                   SEC CL    2.510                                                                             2.084                                                                             1.933                                                                             1.829                                                                             1.645                                                                             1.618                                                                             2.546                                                                             2.108                                                                             1.991                                                                             1.887                                                                             1.755                                                                             1.646                   SEV (C)   0.278                                                                             0.275                                                                             0.252                                                                             0.235                                                                             0.218                                                                             0.210                                                                             0.283                                                                             0.273                                                                             0.250                                                                             0.250                                                                             0.247                                                                             0.235                   r.sup.2   0.010                                                                             0.028                                                                             0.052                                                                             0.076                                                                             0.086                                                                             0.053                                                                             0.006                                                                             0.057                                                                             0.045                                                                             0.052                                                                             0.035                                                                             0.029                   Bias      0.160                                                                             0.160                                                                             0.140                                                                             0.130                                                                             0.120                                                                             0.110                                                                             0.160                                                                             0.150                                                                             0.140                                                                             0.140                                                                             0.130                                                                             0.120                   Bias CL   0.343                                                                             0.337                                                                             0.303                                                                             0.280                                                                             0.260                                                                             0.243                                                                             0.351                                                                             0.330                                                                             0.300                                                                             0.290                                                                             0.280                                                                             0.270                   SEP (C)   0.350                                                                             0.340                                                                             0.310                                                                             0.280                                                                             0.260                                                                             0.250                                                                             0.360                                                                             0.330                                                                             0.300                                                                             0.290                                                                             0.280                                                                             0.270                   Slope     0.127                                                                             0.212                                                                             0.239                                                                             0.252                                                                             0.218                                                                             0.142                                                                             0.102                                                                             0.294                                                                             0.216                                                                             0.212                                                                             0.149                                                                             0.149                   Intercept 3.270                                                                             2.960                                                                             2.850                                                                             2.800                                                                             2.930                                                                             3.210                                                                             3.360                                                                             2.640                                                                             2.940                                                                             2.950                                                                             3.180                                                                             3.190                   R.S.D.    0.234                                                                             0.233                                                                             0.235                                                                             0.236                                                                             1.942                                                                             1.495                                                                             1.736                                                                             1.938                                                                             1.980                                                                             2.030                                                                             2.179                                                                             2.183                   |Bias| - Bias CL                                                      -0.183                                                                            -0.177                                                                            -0.163                                                                            -0.150                                                                            -0.140                                                                            -0.133                                                                            -0.191                                                                            -0.180                                                                            -0.156                                                                            -0.152                                                                            -0.149                                                                            -0.146                  |Bias| < Bias CL?                                                     Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes                     Digestibility of dry matter in vivo                                           Lowest partial F-ratio                                                                  91.59                                                                             9.46                                                                              9.77                                                                              7.10                                                                              2.58                                                                              4.12                                                                              93.60                                                                             6.52                                                                              16.07                                                                             4.36                                                                              4.68                                                                              4.94                    R.sup.2   0.700                                                                             0.867                                                                             0.902                                                                             0.916                                                                             0.927                                                                             0.935                                                                             0.675                                                                             0.815                                                                             0.898                                                                             0.912                                                                             0.922                                                                             0.927                   SEC       3.139                                                                             2.095                                                                             1.794                                                                             1.660                                                                             1.545                                                                             1.457                                                                             3.271                                                                             2.467                                                                             1.828                                                                             1.698                                                                             1.598                                                                             1.546                   SEC CL    2.510                                                                             2.084                                                                             1.933                                                                             1.829                                                                             1.645                                                                             1.618                                                                             2.546                                                                             2.108                                                                             1.991                                                                             1.887                                                                             1.755                                                                             1.646                   SEV (C)   3.332                                                                             2.282                                                                             1.997                                                                             1.830                                                                             1.694                                                                             1.607                                                                             3.357                                                                             2.572                                                                             2.016                                                                             1.905                                                                             1.840                                                                             1.787                   r.sup.2   0.777                                                                             0.856                                                                             0.888                                                                             0.871                                                                             0.887                                                                             0.881                                                                             0.828                                                                             0.831                                                                             0.809                                                                             0.836                                                                             0.877                                                                             0.892                   Bias      1.880                                                                             1.260                                                                             1.080                                                                             1.000                                                                             0.930                                                                             0.870                                                                             1.960                                                                             1.480                                                                             1.100                                                                             1.020                                                                             0.960                                                                             0.930                   Bias CL   0.343                                                                             0.337                                                                             0.303                                                                             0.280                                                                             0.260                                                                             0.243                                                                             0.351                                                                             0.330                                                                             0.296                                                                             0.292                                                                             0.279                                                                             0.266                   SEP (C)   4.080                                                                             2.720                                                                             2.330                                                                             2.160                                                                             2.010                                                                             1.890                                                                             4.250                                                                             3.210                                                                             2.380                                                                             2.210                                                                             2.080                                                                             2.010                   Slope     0.892                                                                             0.880                                                                             0.924                                                                             0.870                                                                             0.851                                                                             0.837                                                                             1.130                                                                             0.991                                                                             0.812                                                                             0.829                                                                             0.840                                                                             0.865                   Intercept 7.380                                                                             6.750                                                                             3.930                                                                             6.850                                                                             8.320                                                                             8.960                                                                             -6.490                                                                            0.210                                                                             9.960                                                                             9.030                                                                             8.710                                                                             7.270                   R.S.D.    2.531                                                                             2.034                                                                             1.791                                                                             1.927                                                                             1.799                                                                             1.848                                                                             2.222                                                                             2.201                                                                             2.344                                                                             2.172                                                                             1.876                                                                             1.761                   |Bias| - Bias CL                                                      1.537                                                                             0.923                                                                             0.777                                                                             0.720                                                                             0.670                                                                             0.627                                                                             1.609                                                                             1.150                                                                             0.804                                                                             0.728                                                                             0.681                                                                             0.664                   |Bias| < Bias CL?                                                     No  No  No  No  No  No  No  No  No  No  No  No                      Digestibility of dry matter in vivo                                           Lowest partial F-ratio                                                                  94.12                                                                             8.62                                                                              16.01                                                                             4.48                                                                              4.61                                                                              5.01                                                                              92.14                                                                             9.60                                                                              9.70                                                                              10.55                                                                             2.67                                                                              4.41                    R.sup.2   0.744                                                                             0.784                                                                             0.856                                                                             0.871                                                                             0.886                                                                             0.901                                                                             0.740                                                                             0.797                                                                             0.842                                                                             0.881                                                                             0.888                                                                             0.900                   SEC       3.568                                                                             3.283                                                                             2.680                                                                             2.532                                                                             2.384                                                                             2.224                                                                             3.598                                                                             3.182                                                                             2.802                                                                             2.430                                                                             2.351                                                                             2.235                   SEC CL    2.510                                                                             2.084                                                                             1.933                                                                             1.829                                                                             1.645                                                                             1.618                                                                             2.546                                                                             2.108                                                                             1.991                                                                             1.887                                                                             1.755                                                                             1.646                   SEV (C)   3.633                                                                             3.371                                                                             2.785                                                                             2.667                                                                             2.563                                                                             2.364                                                                             3.655                                                                             3.280                                                                             2.892                                                                             2.818                                                                             2.525                                                                             2.416                   r.sup.2   0.828                                                                             0.816                                                                             0.813                                                                             0.802                                                                             0.819                                                                             0.851                                                                             0.823                                                                             0.807                                                                             0.810                                                                             0.844                                                                             0.818                                                                             0.823                   Bias      2.140                                                                             1.970                                                                             1.610                                                                             1.520                                                                             1.430                                                                             1.330                                                                             2.160                                                                             1.910                                                                             1.680                                                                             1.460                                                                             1.420                                                                             1.340                   Bias CL   4.585                                                                             4.219                                                                             3.444                                                                             3.254                                                                             3.064                                                                             2.858                                                                             4.621                                                                             4.089                                                                             3.601                                                                             3.123                                                                             3.034                                                                             2.872                   SEP (C)   4.640                                                                             4.270                                                                             3.480                                                                             3.290                                                                             3.100                                                                             2.890                                                                             4.680                                                                             4.140                                                                             3.640                                                                             3.160                                                                             3.070                                                                             2.910                   Slope     0.960                                                                             0.971                                                                             0.906                                                                             0.862                                                                             0.867                                                                             0.864                                                                             0.937                                                                             0.927                                                                             0.882                                                                             0.935                                                                             0.881                                                                             0.841                   Intercept 2.120                                                                             1.280                                                                             4.530                                                                             7.230                                                                             7.380                                                                             7.610                                                                             3.490                                                                             3.660                                                                             5.790                                                                             3.260                                                                             6.140                                                                             8.660                   R.S.D.    2.978                                                                             3.002                                                                             3.088                                                                             2.952                                                                             2.681                                                                             2.922                                                                             3.023                                                                             2.742                                                                             2.959                                                                             2.846                                                                             0.231                                                                             0.239                   |Bias| - Bias CL                                                      -2.445                                                                            -2.49                                                                             -1.834                                                                            -1.734                                                                            -1.634                                                                            -1.528                                                                            -2.461                                                                            -2.179                                                                            -1.921                                                                            -1.663                                                                            -1.614                                                                            -1.532                  |Bias| < Bias CL?                                                     Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes                     __________________________________________________________________________

                                      TABLE 4c                                    __________________________________________________________________________    Calibration and validation statistics (multivariate                           regressions)                                                                          PCR      PLS       MPLS                                                       2, 5, 5                                                                           2, 10, 10                                                                          2, 5, 5                                                                           2, 10, 10                                                                           2, 5, 5                                                                           2, 10, 10                                      __________________________________________________________________________    Energy required to shear                                                      R.sup.2 0.847                                                                             0.752                                                                              0.639                                                                             0.601 0.601                                                                             0.582                                          SEC     1.036                                                                             1.290                                                                              1.545                                                                             1.624 1.550                                                                             1.586                                          SEC CL  1.199                                                                             1.493                                                                              1.788                                                                             1.879 1.793                                                                             1.835                                          SECV    1.750                                                                             1.592                                                                              1.788                                                                             1.933 1.600                                                                             1.583                                          r.sup.2 0.5441                                                                            0.4876                                                                             0.4938                                                                            0.4157                                                                              0.3080                                                                            0.3563                                         Bias    0.620                                                                             0.770                                                                              0.930                                                                             0.970 0.930                                                                             0.950                                          Bias CL 1.331                                                                             1.658                                                                              1.986                                                                             2.087 1.992                                                                             2.038                                          SEP (C) 1.350                                                                             1.680                                                                              2.010                                                                             2.110 2.020                                                                             2.060                                          Slope   0.6540                                                                            0.6850                                                                             0.7390                                                                            0.6270                                                                              0.5220                                                                            0.6000                                         Intercept                                                                             5.2900                                                                            4.8100                                                                             3.7500                                                                            5.4500                                                                              7.3100                                                                            6.0200                                         R.S.D.  1.671                                                                             1.776                                                                              1.761                                                                             1.892 2.065                                                                             1.992                                          |Bias| - Bias CL                                                    -0.711                                                                            -0.888                                                                             -1.056                                                                            -1.117                                                                              -1.062                                                                            -1.088                                         |Bias| < Bias CL?                                                   Yes Yes  Yes Yes   Yes Yes                                            Energy required to comminute                                                  R.sup.2 0.584                                                                             0.574                                                                              0.605                                                                             0.595 0.556                                                                             0.558                                          SEC     23.378                                                                            23.682                                                                             22.788                                                                            23.075                                                                              24.164                                                                            24.101                                         SEC CL  27.048                                                                            27.400                                                                             26.366                                                                            26.698                                                                              27.958                                                                            27.885                                         SECV    26.030                                                                            26.121                                                                             25.548                                                                            25.683                                                                              26.409                                                                            26.252                                         r.sup.2 0.349                                                                             0.337                                                                              0.332                                                                             0.325 0.33                                                                              0.328                                          Bias    14.030                                                                            14.210                                                                             13.670                                                                            13.840                                                                              14.500                                                                            14.460                                         Bias CL 30.044                                                                            30.435                                                                             29.286                                                                            29.655                                                                              31.055                                                                            30.974                                         SEP (C) 30.390                                                                            30.790                                                                             29.620                                                                            30.000                                                                              31.410                                                                            31.330                                         Slope   0.649                                                                             0.636                                                                              0.644                                                                             0.632 0.657                                                                             0.638                                          Intercept                                                                             37.3                                                                              39.2 38.1                                                                              39.7  36.6                                                                              39.1                                           R.S.D.  28.246                                                                            28.676                                                                             28.714                                                                            28.884                                                                              28.651                                                                            28.900                                         |Bias| - Bias CL                                                    -16.014                                                                           -16.225                                                                            -15.616                                                                           -15.815                                                                             -16.555                                                                           -16.514                                        |Bias| < Bias CL?                                                   Yes Yes  Yes Yes   Yes Yes                                            Energy required to compress                                                   R.sup.2 0.251                                                                             0.160                                                                              0.231                                                                             0.208 0.038                                                                             0.040                                          SEC     0.225                                                                             0.241                                                                              0.265                                                                             0.269 0.260                                                                             0.260                                          SEC CL  0.260                                                                             0.279                                                                              0.307                                                                             0.311 0.301                                                                             0.301                                          SECV    0.299                                                                             0.277                                                                              0.301                                                                             0.307 0.301                                                                             0.299                                          r.sup.2 0.0220                                                                            0.0120                                                                             0.0130                                                                            0.0090                                                                              0.0060                                                                            0.0080                                         Bias    0.140                                                                             0.140                                                                              0.160                                                                             0.160 0.160                                                                             0.160                                          Bias CL 0.289                                                                             0.310                                                                              0.341                                                                             0.346 0.334                                                                             0.334                                          SEP (C) 0.290                                                                             0.310                                                                              0.340                                                                             0.350 0.340                                                                             0.340                                          Slope   0.2290                                                                            0.2270                                                                             0.1530                                                                            0.1330                                                                              0.2290                                                                            0.2590                                         Intercept                                                                             2.8900                                                                            2.9000                                                                             3.1700                                                                            3.2500                                                                              2.8900                                                                            2.7700                                         R.S.D.  0.235                                                                             0.236                                                                              0.236                                                                             0.237 0.237                                                                             0.237                                          |Bias| - Bias CL                                                    -0.149                                                                            -0.170                                                                             -0.181                                                                            -0.186                                                                              -0.174                                                                            -0.174                                         |Bias| < Bias CL?                                                   Yes Yes  Yes Yes   Yes Yes                                            Digestibility of dry matter in vivo                                           R.sup.2 0.909                                                                             0.900                                                                              0.958                                                                             0.937 0.571                                                                             0.892                                          SEC     1.638                                                                             1.711                                                                              1.109                                                                             1.356 3.756                                                                             1.911                                          SEC CL  1.895                                                                             1.980                                                                              1.283                                                                             1.569 4.346                                                                             2.211                                          SECV    2.159                                                                             2.075                                                                              1.957                                                                             1.776 3.797                                                                             2.180                                          r.sup.2 0.9022                                                                            0.8865                                                                             0.8447                                                                            0.8457                                                                              0.6963                                                                            0.8671                                         Bias    0.980                                                                             1.030                                                                              0.670                                                                             0.810 2.250                                                                             1.150                                          Bias CL 2.105                                                                             2.199                                                                              1.425                                                                             1.743 4.827                                                                             2.456                                          SEP (C) 2.130                                                                             2.220                                                                              1.440                                                                             1.760 4.880                                                                             2.480                                          Slope   0.848                                                                             0.807                                                                              0.839                                                                             0.822 0.981                                                                             0.745                                          Intercept                                                                             8.77                                                                              11.1 8.65                                                                              9.41  1.99                                                                              14.6                                           R.S.D.  1.704                                                                             1.834                                                                              2.143                                                                             2.139 2.914                                                                             1.984                                          |Bias| - Bias CL                                                    -1.125                                                                            -1.169                                                                             -0.755                                                                            -0.933                                                                              -2.577                                                                            -1.306                                         |Bias| < Bias CL?                                                   Yes Yes  Yes Yes   Yes Yes                                            Digestibility of dry matter in vitro                                          R.sup.2 0.820                                                                             0.790                                                                              0.780                                                                             0.760 0.420                                                                             0.490                                          SEC     2.880                                                                             3.100                                                                              3.330                                                                             3.470 5.380                                                                             4.850                                          SEC CL  3.332                                                                             3.587                                                                              3.853                                                                             4.015 6.225                                                                             5.611                                          SECV    3.170                                                                             3.560                                                                              3.830                                                                             3.900 5.690                                                                             4.780                                          r.sup.2 0.8120                                                                            0.7730                                                                             0.8530                                                                            0.8040                                                                              0.6910                                                                            0.6690                                         Bias    1.730                                                                             1.860                                                                              2.000                                                                             2.080 3.230                                                                             2.910                                          Bias CL 3.701                                                                             3.984                                                                              4.280                                                                             4.459 6.914                                                                             6.233                                          SEP (C) 3.740                                                                             4.030                                                                              4.330                                                                             4.510 6.990                                                                             6.310                                          Slope   0.9180                                                                            0.9840                                                                             0.9530                                                                            0.6120                                                                              1.1200                                                                            0.8650                                         Intercept                                                                             3.4700                                                                            -0.3600                                                                            2.3100                                                                            4.6300                                                                              -7.5100                                                                           6.1800                                         R.S.D.  3.053                                                                             3.363                                                                              2.836                                                                             3.089 3.911                                                                             4.002                                          |Bias| - Bias CL                                                    -1.971                                                                            -2.124                                                                             -2.280                                                                            -2.379                                                                              -3.684                                                                            -3.323                                         |Bias| < Bias CL?                                                   Yes Yes  Yes Yes   Yes Yes                                            __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________    Standard error of laboratory determination (SEL)                                                            Digestibility                                                                       Digestibility                                          Energy                                                                             Energy                                                                              Energy                                                                              of dry                                                                              of dry                                                 required to                                                                        required to                                                                         required to                                                                         matter                                                                              matter                                                 shear                                                                              comminute                                                                           compress                                                                            in vivo                                                                             in vitro                                               (kJ/m.sup.2)                                                                       (kJ/kg DM)                                                                          (kJ/kg DM)                                                                          (%)   (%)                                       __________________________________________________________________________    Mean SEL (n = 65)                                                                          0.796                                                                              5.830 0.078 not available                                                                       0.314                                     Median SEL   0.788                                                                              5.492 0.085 not available                                                                       0.270                                     Maximum SEL  2.044                                                                              13.098                                                                              0.211 not available                                                                       1.126                                     Minimum SEL  0.114                                                                              0.780 0.019 not available                                                                       0.005                                     SEL CL (using mean SEL)                                                                    1.035                                                                              7.319 0.101 not available                                                                       0.408                                     SEL CL (using median SEL)                                                                  1.024                                                                              7.140 0.111 not available                                                                       0.351                                     __________________________________________________________________________

                                      TABLE 6a                                    __________________________________________________________________________    Components of possible prediction equations                                   from stepwise and step-up regression analyses.                                           Coefficient                                                                         Wavelength                                                                           Coefficient                                                                         Wavelength                                      __________________________________________________________________________               Energy required to shear                                           Regression analysis                                                                      Stepwise     Step-up                                               Mathematical treatment                                                                   2, 2, 2 (6 terms)                                                                          2, 5, 5 (2 terms)                                     __________________________________________________________________________               19.95        28.09                                                            2452.05                                                                             2048   1035.77                                                                             2048                                                       -4255.81                                                                            1598   700.12                                                                              1958                                                       3823.49                                                                             1458                                                                    -5319.88                                                                            1718                                                                    5148.38                                                                             1828                                                                    10239.46                                                                            1168                                                         __________________________________________________________________________               Energy required to compress                                        Regression analysis                                                                      Stepwise     Step-up                                               Mathematical treatment                                                                   2, 10, 10 (4 terms)                                                                        2, 10, 5 (3 terms)                                    __________________________________________________________________________               -0.71        2.49                                                             -28.02                                                                              2278   -31.05                                                                              1728                                                       112.57                                                                              1588   -108.89                                                                             1548                                                       -79.48                                                                              1728   -105.95                                                                             1268                                                             -911.04                                                                              1268                                                  __________________________________________________________________________               Energy required to comminute                                       Regression analysis                                                                      Stepwise     Step-up                                               Mathematical treatment                                                                   2, 10, 5 (4 terms)                                                                         2, 10, 5 (1 term)                                     __________________________________________________________________________               231.42       49.16                                                            -3005.37                                                                            2128   -1521.33                                                                            2268                                                       4290.19                                                                             2408                                                                    -4955.12                                                                            2018                                                                    18224.74                                                                            1138                                                         __________________________________________________________________________               Digestibility of dry matter in vivo                                Regression analysis                                                                      Stepwise     Step-up                                               Mathematical treatment                                                                   2, 5, 5 (6 terms)                                                                          2, 10, 5 (3 terms)                                    __________________________________________________________________________               48.62        49.15                                                            -387.08                                                                             1918   -612.43                                                                             1698                                                       -8799.69                                                                            1238   252.82                                                                              1418                                                       8152.72                                                                             1158   -943.77                                                                             1618                                                       1249.01                                                                             1668                                                                    519.46                                                                              1908                                                                    -181.84                                                                             2248                                                         __________________________________________________________________________               Digestibility of dry matter in vitro                               Regression analysis                                                                      Stepwise     Step-up                                               Mathematical treatment                                                                   2, 2, 5 (5 terms)                                                                          2, 10, 10 (4 terms)                                   __________________________________________________________________________               63.43        54.29                                                            -558.01                                                                             1918   -1171.70                                                                            1698                                                       981.30                                                                              1908   311.12                                                                              1418                                                       -2186.89                                                                            1898   -2657.69                                                                            1618                                                       2003.05                                                                             2158   -2319.81                                                                            1228                                                       -1491.99                                                                            1748                                                         __________________________________________________________________________

                                      TABLE 6b                                    __________________________________________________________________________    Components of possible prediction equations from multivariate regression      analyses.                                                                     __________________________________________________________________________    Energy required to shear                                                                  Energy required to compress                                                                Energy required to comminute                         PCR (2,5,5) PCR (2,5,5)  PCR (2,5,5) PLS (2,5,5)                              Coefficient                                                                         Wavelength                                                                          Coefficient                                                                         Wavelength                                                                           Coefficient                                                                         Wavelength                                                                          Coefficient                                                                         Wavelength                         __________________________________________________________________________    -3.33       3.35         -22.8       -16.44                                   18.1  1108  0.17  1108   93.07 1108  91.01 1108                               1.76  1118  0.02  1118   6.5   1118  7.19  1118                               -0.2  1128  -0.01 1128   -7.27 1128  -5.63 1128                               -0.84 1138  -0.01 1138   -0.79 1138  -0.13 1138                               1.15  1148  0.01  1148   3.98  1148  5.58  1148                               -0.85 1158  -0.01 1158   -10.39                                                                              1158  -8.55 1158                               0.13  1168  0     1168   -4.8  1168  -4.72 1168                               0.64  1178  0.03  1178   13.75 1178  13.27 1178                               -0.04 1188  0.04  1188   19.07 1188  17.38 1188                               -0.84 1198  0     1198   5.06  1198  0.44  1198                               -1.14 1208  -0.03 1208   -8.92 1208  -13.96                                                                              1208                               -1.71 1218  -0.05 1218   -20.83                                                                              1218  -23.8 1218                               -1.73 1228  -0.04 1228   -17.9 1228  -15.15                                                                              1228                               -0.85 1238  -0.01 1238   -3.26 1238  -0.82 1238                               0.12  1248  0     1248   -0.85 1248  1.6   1248                               0.5   1258  0     1258   -2.55 1258  -0.82 1258                               -0.9  1268  -0.01 1268   -4.67 1268  -3.84 1268                               -1.25 1278  0     1278   1.29  1278  1.1   1278                               -0.25 1288  0.01  1288   5.24  1288  4.93  1288                               0.2   1298  0.02  1298   5.9   1298  7.12  1298                               -0.1  1308  0.03  1308   9.22  1308  10.4  1308                               -0.66 1318  0.04  1318   14.26 1318  16.14 1318                               1.25  1328  0.06  1328   22.7  1328  23.58 1328                               5     1338  0.07  1338   27.63 1338  27.65 1338                               2.34  1348  0.03  1348   6.64  1348  10.27 1348                               -2.37 1358  -0.06 1358   -26.23                                                                              1358  -24.35                                                                              1358                               -10.62                                                                              1368  -0.15 1368   -66.36                                                                              1368  -60.7 1368                               -9.89 1378  -0.01 1378   -1.83 1378  2.2   1378                               -1.68 1388  0.16  1388   67.77 1388  67.91 1388                               8.65  1398  0.3   1398   125.67                                                                              1398  115.99                                                                              1398                               23.88 1408  0.49  1408   188.24                                                                              1408  174.79                                                                              1408                               13.87 1418  0.2   1418   67.19 1418  62.69 1418                               -12.53                                                                              1428  -0.37 1428   -153.54                                                                             1428  -139.99                                                                             1428                               -0.01 1438  -0.39 1438   -145.28                                                                             1438  -137.82                                                                             1438                               -1.04 1448  -0.21 1448   -66.74                                                                              1448  -75.27                                                                              1448                               2.09  1458  -0.13 1458   -37.31                                                                              1458  -47.38                                                                              1458                               -2.69 1468  -0.11 1468   -49.09                                                                              1468  -48.54                                                                              1468                               -8.05 1478  -0.14 1478   -70.4 1478  -59.94                                                                              1478                               -1.2  1488  -0.06 1488   -26.64                                                                              1488  -26.06                                                                              1488                               -2.08 1498  -0.01 1498   -1.87 1498  -3.2  1498                               -1.69 1508  0.01  1508   4.61  1508  3.33  1508                               0.35  1518  0.07  1518   28.69 1518  26.91 1518                               2.8   1528  0.12  1528   49.84 1528  48.03 1528                               -0.01 1538  0.08  1538   34.38 1538  33.02 1538                               -1.83 1548  0     1548   -3.32 1548  0.49  1548                               -3.7  1558  -0.04 1558   -21.79                                                                              1558  -17.62                                                                              1558                               -0.66 1568  -0.01 1568   -4.61 1568  -3.35 1568                               -1.99 1578  -0.04 1578   -13.08                                                                              1578  -15.39                                                                              1578                               -3.67 1588  -0.09 1588   -43.91                                                                              1588  -40.21                                                                              1588                               -5.26 1598  -0.07 1598   -3.02 1598  -32.77                                                                              1598                               0.06  1608  -0.01 1608   -7.28 1608  -5.93 1608                               2.89  1618  0.04  1618   17.4  1618  15    1618                               0.22  1628  0.09  1628   34.68 1628  33.13 1628                               -0.98 1638  0.13  1638   49.47 1638  48.83 1638                               10.23 1648  0.1   1648   53.35 1648  44.32 1648                               10.67 1658  0     1658   -3.16 1658  -2.24 1658                               6.52  1668  -0.22 1668   -82.09                                                                              1668  -80.94                                                                              1668                               -20.53                                                                              1678  -0.07 1678   -60.38                                                                              1678  -38.22                                                                              1678                               -6.15 1688  0.15  1688   55.65 1688  60.49 1688                               7.4   1698  0.06  1698   48.43 1698  42.6  1698                               4.76  1708  0.06  1708   34.19 1708  27.79 1708                               -19.73                                                                              1718  -0.09 1718   -54.88                                                                              1718  -46.36                                                                              1718                               -5.98 1728  -0.13 1728   -54.69                                                                              1728  -69.44                                                                              1728                               19.24 1738  0.15  1738   78.27 1738  63.67 1738                               6.42  1748  0.19  1748   90.94 1748  91.13 1748                               -3.1  1758  0.06  1758   21.41 1758  20.27 1758                               -4.03 1768  -0.1  1768   -47.2 1768  -48.58                                                                              1768                               -1.47 1778  -0.11 1778   -42.48                                                                              1778  -39.05                                                                              1778                               -0.44 1788  -0.09 1788   -36.22                                                                              1788  -33.03                                                                              1788                               1.72  1798  -0.01 1798   -2.33 1798  -3.76 1798                               2.76  1808  0.05  1808   20.97 1808  18.41 1808                               -3.79 1818  -0.01 1818   -6.58 1818  -5.17 1919                               -4.32 1828  -0.07 1828   -30.81                                                                              1828  -26.5 1828                               -2.97 1838  -0.05 1838   -17.29                                                                              1838  -17.64                                                                              1838                               1.97  1848  0.03  1848   17.65 1848  15.59 1848                               -2.48 1858  0.06  1858   28.06 1858  28.11 1858                               -6.48 1868  0.08  1868   42.2  1868  40.46 1868                               -0.22 1878  0.23  1878   115.52                                                                              1878  108.98                                                                              1878                               -1.64 1888  0.44  1888   219.15                                                                              1888  208.1 1888                               31.11 1898  0.2   1898   98.82 1898  99.42 1898                               2.3   1908  -0.35 1908   -179.9                                                                              1908  -157.11                                                                             1908                               -25.69                                                                              1918  -0.47 1918   -251.3                                                                              1918  -220.58                                                                             1918                               -12.22                                                                              1928  -0.34 1928   -171.93                                                                             1928  -172.09                                                                             1928                               15.11 1938  -0.14 1938   -55.38                                                                              1938  -77.27                                                                              1938                               28.89 1948  -0.03 1948   -6.17 1948  -23.21                                                                              1948                               27.72 1958  -0.04 1958   -16.65                                                                              1958  -19.03                                                                              1958                               8.93  1968  0.05  1968   12.02 1968  22.46 1968                               -15.33                                                                              1978  0.23  1978   68.03 1978  88.88 1978                               -9.25 1988  0.29  1988   85.84 1988  103.6 1988                               -3.33 1998  0.27  1998   78.68 1998  98.03 1998                               1.28  2008  0.32  2008   97.53 2008  115.14                                                                              2008                               20.22 2018  0.25  2018   104.79                                                                              2018  99.25 2018                               18.34 2028  0.08  2028   42.08 2028  33.39 2028                               9.58  2038  -0.01 2038   23.98 2038  11.1  2038                               5.59  2048  0.13  2048   101.85                                                                              2048  77.38 2048                               -8.64 2108  -0.26 2108   -108.06                                                                             2108  -107.49                                                                             2108                               -6.28 2118  -0.23 2118   -91.06                                                                              2118  -91.23                                                                              2118                               -4.49 2128  -0.23 2128   -97.55                                                                              2128  -93.37                                                                              2128                               -16.58                                                                              2138  -0.2  2138   -101.35                                                                             2138  -85.08                                                                              2138                               -9.08 2148  -0.01 2148   -13.78                                                                              2148  -9.31 2148                               -2.68 2158  0.08  2158   37.5  2158  36.99 2158                               3.19  2168  0.26  2168   118.43                                                                              2168  110.03                                                                              2168                               4.27  2178  0.26  2178   122.68                                                                              2178  109.87                                                                              2178                               -6.3  2188  0.16  2188   54.73 2188  58.98 2188                               -13.33                                                                              2198  0.15  2198   38.08 2198  53.78 2198                               -2.74 2208  0.35  2208   129.58                                                                              2208  147.19                                                                              2208                               35.77 2218  0.36  2218   171.77                                                                              2218  149.55                                                                              2218                               30.36 2228  0.42  2228   182.8 2228  168.64                                                                              2228                               22.91 2238  0.22  2238   73.19 2238  88.39 2238                               98.61 2248  -0.67 2248   -152.9                                                                              2248  -250.89                                                                             2248                               -15.77                                                                              2258  -0.47 2258   -184.5                                                                              2258  -189.12                                                                             2258                               -85.22                                                                              2268  -0.2  2268   -167.23                                                                             2268  -101.11                                                                             2268                               -35.1 2278  -0.45 2278   -214.87                                                                             2278  -180.14                                                                             2278                               27.27 2288  0.22  2288   148   2288  122.32                                                                              2288                               4.27  2298  0.84  2298   352.88                                                                              2298  341.16                                                                              2298                               -13.06                                                                              2308  0.29  2308   78.88 2308  63.66 2308                               0.67  2318  -0.48 2318   -208.27                                                                             2318  -207.81                                                                             2318                               -13.34                                                                              2328  -0.47 2328   -167.95                                                                             2328  -150.99                                                                             2328                               -23.3 2338  -0.2  2338   -79.26                                                                              2338  -66.98                                                                              2338                               0.66  2348  0.15  2348   62.44 2348  40.83 2348                               7.98  2358  -0.07 2358   -23.09                                                                              2358  -30.25                                                                              2358                               -15.62                                                                              2368  0.08  2368   25.53 2368  41.9  2368                               -16.39                                                                              2378  0.05  2378   -3.86 2378  12.67 2378                               -4.44 2388  -0.05 2388   -33.15                                                                              2388  -26.65                                                                              2388                               21.16 2398  0.2   2398   98.53 2398  79.92 2398                               49.9  2408  0.22  2408   130.87                                                                              2408  89.16 2408                               22.34 2418  0.29  2418   120.05                                                                              2418  107.71                                                                              2418                               -1.47 2428  0.22  2428   72.57 2428  84.86 2428                               17.19 2438  0.03  2438   6.72  2438  3.78  2438                               15.21 2448  0.11  2448   55.93 2448  45.74 2448                               -14.12                                                                              2458  0.16  2458   59.89 2458  71.29 2458                               -24.15                                                                              2468  -0.04 2468   -31.79                                                                              2468  -13.92                                                                              2468                               __________________________________________________________________________    Digestibility of dry matter in vitro                                                            Digestibility of dry matter in vivo                         PLS (2,5,5)       PCR (2,5,5)    PLS (2,5,5)                                  Coefficient                                                                          Wavelength Coefficient                                                                         Wavelength                                                                             Coefficient                                                                         Wavelength                             __________________________________________________________________________    59.77             40.56          63.64                                        -96.26 1108       -161.5                                                                              1108     -78.7 1108                                   7.55   1118       12.91 1118     4     1118                                   12.25  1128       22.04 1128     8.68  1128                                   6.85   1138       19.51 1138     3.94  1138                                   6.74   1148       8.19  1148     7.08  1148                                   11.89  1158       5.29  1158     6.24  1158                                   4.45   1168       -0.92 1168     0.43  1168                                   -10.08 1178       -11.1 1178     -5.6  1178                                   -29.6  1188       -37.4 1188     -15.1 1188                                   -20.43 1198       -26.13                                                                              1198     -10.61                                                                              1198                                   -20.05 1208       -38.03                                                                              1208     -15.98                                                                              1208                                   -15.65 1218       -35.64                                                                              1218     -13.18                                                                              1218                                   2.41   1228       -13.39                                                                              1228     2.03  1228                                   6.62   1238       0.89  1238     6.37  1238                                   8.8    1248       14.13 1248     7.08  1248                                   7.47   1258       17.48 1258     5.09  1258                                   -1.32  1268       -7.44 1268     -0.25 1268                                   -7.39  1278       -22.67                                                                              1278     -4.08 1278                                   -0.79  1288       -1.05 1288     0.15  1288                                   3.48   1298       9.23  1298     3.72  1298                                   5.1    1308       13.17 1308     4.38  1308                                   8.23   1318       16.6  1318     6.03  1318                                   8.48   1328       25.91 1328     9.03  1328                                   17.78  1338       40.71 1338     13    1338                                   24.61  1348       51.12 1348     13.51 1348                                   -0.07  1358       4.6   1358     0.20  1358                                   -23.89 1368       -88.33                                                                              1368     -13.81                                                                              1368                                   -29.88 1378       -68.78                                                                              1378     -8.13 1378                                   -18.97 1388       6.08  1388     -1.4  1388                                   23.92  1398       32.14 1398     18.06 1398                                   60.7   1408       78.51 1408     32.08 1408                                   55.51  1418       90.64 1418     11.94 1418                                   -0.3   1428       -1.47 1428     -14.78                                                                              1428                                   -28.21 1438       -11.15                                                                              1438     -19.94                                                                              1438                                   -32.57 1448       10.5  1448     -19.24                                                                              1448                                   -28.08 1458       18.31 1458     -18.15                                                                              1458                                   1.48   1468       -3.82 1468     3.7   1468                                   18.21  1478       -18.48                                                                              1478     10.65 1478                                   -0.65  1488       -25.14                                                                              1488     -0.75 1488                                   -22.99 1498       -74.43                                                                              1498     -7.65 1498                                   -23.44 1508       -75.49                                                                              1508     -9.41 1508                                   -15.74 1518       -58.78                                                                              1518     -8.06 1518                                   -9.09  1528       -25.77                                                                              1528     -5.21 1528                                   -2.8   1538       -7.83 1538     -3.83 1538                                   10.62  1548       17.83 1548     4.58  1548                                   28.76  1558       52.96 1558     15.5  1558                                   5.02   1568       21.09 1588     15.5  1558                                   -6.6   1578       -27.42                                                                              1578     -3.09 1578                                   -18.09 1588       -42.59                                                                              1588     -5.77 1588                                   -9.26  1598       -63.69                                                                              1598     -8.48 1598                                   -6.66  1608       -3.06 1608     -0.65 1608                                   -3.82  1618       -1.82 1618     -0.67 1618                                   -3.58  1628       -2.81 1628     0.24  1628                                   0.55   1638       -9.18 1638     3.42  1638                                   0.5    1648       13.81 1648     0.66  1648                                   23.87  1658       61.39 1658     13.12 1658                                   54.92  1668       159.6 1668     28.91 1668                                   78.64  1678       101.05                                                                              1678     44.01 1678                                   -13.9  1688       -79.38                                                                              1688     -8.19 1688                                   -74.54 1698       -77.73                                                                              1698     -34   1698                                   -38.63 1708       -43.87                                                                              1708     -18.38                                                                              1708                                   -24.48 1718       21.34 1718     2.17  1718                                   -17.91 1728       -25.8 1728     -31.77                                                                              1728                                   -43.01 1738       -40.51                                                                              1738     -21.21                                                                              1738                                   '29.25 1748       -28.11                                                                              1748     -5.24 1748                                   -16.33 1758       -4.55 1758     -11.67                                                                              1758                                   0.43   1768       2.68  1768     -0.49 1768                                   28.21  1778       20.91 1778     21.37 1778                                   18.92  1788       13.59 1788     13.25 1788                                   0.54   1798       9.35  1798     -0.93 1798                                   -2.44  1808       7.17  1808     -4.5  1808                                   -2.72  1818       -15.30                                                                              1818     -2.3  1818                                   -5.84  1828       -29.4 1828     -3.37 1828                                   -4.37  1838       -16.21                                                                              1838     -0.05 1838                                   -8.79  1848       2.3   1848     -2.23 1848                                   -7.72  1858       -0.87 1858     -3.79 1858                                   -29.93 1868       -21.29                                                                              1868     -9.61 1868                                   -98.16 1878       -82.33                                                                              1878     -34.58                                                                              1878                                   -116.18                                                                              1888       -102.15                                                                             1888     -52.89                                                                              1888                                   117.59 1898       211.27                                                                              1898     38.2  1898                                   185    1908       204.51                                                                              1908     68.78 1908                                   33.91  1918       -3.12 1918     28.1  1918                                   -35.31 1928       18.14 1928     -3.79 1928                                   -44.59 1938       35.39 1938     -19.45                                                                              1938                                   -9.28  1948       -8.24 1948     -8.41 1948                                   35.73  1958       -11.32                                                                              1948     15.95 1958                                   28.56  1968       -37.15                                                                              1968     13.49 1968                                   10.68  1978       -44.28                                                                              1978     2.03  1978                                   10.98  1988       -61.81                                                                              1988     0.57  1988                                   65.12  1998       -72.2 1998     31.07 1998                                   83.13  2008       -63.31                                                                              2008     38.57 2008                                   7.23   2018       37.37 2018     -1.21 2018                                   0.99   2028       183.21                                                                              2028     -9.38 2028                                   -10.85 2038       156.66                                                                              2038     -14.51                                                                              2038                                   -84.48 2048       -2.09 2048     -54.72                                                                              2048                                   -122.91                                                                              2058       -178.03                                                                             2058     -68.29                                                                              2058                                   -35.85 2068       -104.9                                                                              2068     -1.09 2068                                   34.93  2078       -7.7  2078     37.65 2078                                   28.83  2088       82.28 2088     27.17 2088                                   18.03  2098       54.28 2098     18.01 2098                                   5.09   2108       14.14 2108     15.52 2108                                   -9.58  2118       -40.31                                                                              2118     7.88  2118                                   9.79   2128       2.34  2128     13.25 2128                                   23.04  2138       28.94 2138     18.49 2138                                   -10.93 2148       -31.56                                                                              2148     -8.42 2148                                   -10.97 2158       3.05  2158     -9.12 2158                                   -41.78 2168       -68.48                                                                              2168     -27.35                                                                              2168                                   -46.69 2178       -107.52                                                                             2178     -32.56                                                                              2178                                   -14.5  2188       -54.54                                                                              2188     -12.58                                                                              2188                                   -0.14  2198       -11.17                                                                              2198     4.5   2198                                   -7.15  2208       -2.14 2208     4.87  2208                                   -48.05 2218       -43.68                                                                              2218     -30.89                                                                              2218                                   -18.22 2228       -0.01 2228     -19.94                                                                              2228                                   88.33  2238       100.18                                                                              2238     14.80 2238                                   -24.11 2248       53.32 2248     -53.79                                                                              2248                                   55.09  2258       81.52 2258     18.08 2258                                   110.06 2268       48.93 2268     90.27 2268                                   52.18  2278       -9.18 2278     83.96 2278                                   -89.38 2288       25.1  2288     -35.59                                                                              2288                                   -109.09                                                                              2298       -47.83                                                                              2298     -77.98                                                                              2298                                   -54.11 2308       -23.3 2308     -61.38                                                                              2308                                   17.63  2318       -73.92                                                                              2318     22.34 2318                                   23.71  2328       -23.74                                                                              2328     46.6  2328                                   62.19  2338       13.84 2338     37.70 2338                                   -58.18 2348       -21.67                                                                              2348     -48.16                                                                              2348                                   -21.28 2358       -77.29                                                                              2358     -7.88 2358                                   4.01   2368       -88.75                                                                              2368     18.34 2368                                   32.53  2378       28.42 2378     17.8  2378                                   35.58  2388       68.01 2388     1.95  2388                                   -21.25 2398       22.17 2398     -27.54                                                                              2398                                   -70.01 2408       -28.96                                                                              2408     -50.39                                                                              2408                                   -18.88 2418       8.02  2418     -18.09                                                                              2418                                   61.66  2428       75.99 2428     17.75 2428                                   14.94  2438       58.83 2438     -3.66 2438                                   -11.88 2448       8.46  2448     -11.21                                                                              2448                                   5.35   2458       -4.33 2458     3.97  2458                                   10.49  2468       -33.25                                                                              2468     11.29 2468                                   __________________________________________________________________________

                                      TABLE 7                                     __________________________________________________________________________    Descriptions of forages used in Table 8.                                      Sample                                                                        in                          Part of                                           Table 8                                                                           Genus                                                                              Species                                                                            Variety                                                                             Common name                                                                           plant                                                                             Process undergone                                                                      Stage of maturity                                                                            Regrowth              __________________________________________________________________________    1   Panicum                                                                            coloratum                                                                          Kabutabula                                                                          Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                      mid bloom (9 weeks' regrowth)                                                                mid bloom -                         CPI 16796                                 regrowth              2   Pancium                                                                            maximum                                                                            Colonlao                                                                            Guinea grass                                                                          aerial                                                                            dreid and chaffed                                                                      vegetative regrowth (4                                                                       vegetative                                                                    regrowth              3   Panicum                                                                            coloratum                                                                          Babbalsi                                                                            Makarlkari grass                                                                      aerial                                                                            dried and chaffed                                                                      mid bloom (1 month's                                                                         mid bloom -                                                                   regrowth              4   Panicum                                                                            maximum                                                                            Hamii Guinea grass                                                                          aerial                                                                            dried and chaffed                                                                      early bloom (1 month's                                                                       early bloom -                                                                 regrowth              5   Pancium                                                                            coloratum                                                                          Burnett                                                                             Makarikari grass                                                                      aerial                                                                            dried and chaffed                                                                      mid bloom (6 weeks' regrowth)                                                                mid bloom -                    var                                            regrowth                       Makeri-                                                                       kariense                                                             6   Pancium                                                                            maximum                                                                            Petrie                                                                              Green Panic                                                                           aerial                                                                            dried and chaffed                                                                      mid bloom (4 weeks' regrowth)                                                                mid bloom -                    var.                                           regrowth                       tricho-                                                                       glume                                                                __________________________________________________________________________

                                      TABLE 8                                     __________________________________________________________________________    Examples of energy required to shear, digestibility of dry matter in          vivo,                                                                         forage consumption constraint (FCC), and voluntary feed consumption           (VFC)                                                                             Energy required to                                                                      Digestibility of dry                                            Sample                                                                            shear,    matter in vivo,                                                 in  predicted using NIR.sup.1                                                               predicted using NIR.sup.2                                                               Predicted FCC.sup.3                                                                   Predicted VFC.sup.5                                                                   Actual VFC                                                                            Actual VFC                    Table 7                                                                           (kJ/m.sup.2)                                                                            (%)       (g OM/d/MBW).sup.4                                                                    (g OM/d/MBW)                                                                          (g OM/d/MBW)                                                                          (g OM/d)                      __________________________________________________________________________    1   20.51     51.29     86.85   32.52   30.77   534                           2   16.70     54.73     66.92   44.95   39.47   686                           3   13.75     56.69     51.49   56.51   48.79   848                           4   13.18     59.59     48.41   54.34   53.58   931                           5   17.52     65.18     71.21   39.74   43.66   759                           6   16.63     55.88     66.55   43.01   45.66   793                           __________________________________________________________________________     .sup.1 Predicted using the calibration equation from stepwise regression      analysis (Table 6a).                                                          .sup.2 Predicted using the calibration equation from stepwise regression      analysis (Table 6a).                                                          .sup.3 Predicted using predicted energy required to shear, and the            relationship between energy required to shear and FCC.                        .sup.4 Calculated from predicted FCC and predicted digestibility of dry       matter in vivo.                                                               .sup.5 Abbreviations used: organic matter (OM), metabolic body weight         (MBW) = BW.sup.0.75                                                      

The claims of the invention are as follows:
 1. A method for determininga biomechanical property of a feed, the biomechanical property being onethat reflects how easy it is for an animal to chew the feed, the methodcomprising the steps of:(a) subjecting the feed to infrared radiation toobtain spectral data; and (b) using the spectral data to determine thebiomechanical property; whereby, the biomechanical property of the feedis determined on the basis of the bond energies of the chemicalconstituents of the feed.
 2. A method according to claim 1 wherein thebiomechanical property is selected from the group comprising; shearenergy, compression energy, communication energy, tensile strength,shear strength and intrinsic shear strength.
 3. A method according toclaim 1 wherein the biomechanical property of the feed is determineddirectly from the spectral data.
 4. A method according to claim 1wherein the spectral data is used to determine another property of thefeed and the other property is used to determine the biomechanicalproperty on the basis of a correlation between the other property andthe biomechanical property.
 5. A method according to claim 4 wherein theother property is ADF content, NDF content or lignin content.
 6. Amethod according to claim 1 wherein the spectral data is a reflectancespectrum over a predetermined range of wavelengths.
 7. A methodaccording to claim 6 wherein the predetermined range is approximately700 nm to 3000 nm.
 8. A method according to claim 6 wherein thepredetermined range is approximately 1100 nm to 2500 nm.
 9. A methodaccording to claim 6 wherein the data obtained for the spectral range ofapproximately 1850 nm to 1970 nm is disregarded.
 10. A method accordingto claim 6 wherein the spectral data is recorded at 2 nm intervals overthe predetermined range.
 11. A method according to claim 1 wherein thespectral data is a reflectance spectrum and a reflectance reading istaken at a combination of wavelengths.
 12. A method according to claim11 wherein the combination of wavelengths is selected from the groupcomprising: 1168 nm, 1458 nm, 1598 nm, 1718 nm, 1828 nm, 2048 nm, 1138nm, 2018 nm, 2128 nm, 2408 nm, 1268 nm, 1588 nm, 1728 nm, 2278 nm, 1158nm, 1238 nm, 1668 nm, 1908 nm, 2248 nm, 1698 nm, 1748 nm, 1918 nm and2158 nm.
 13. A method according to claim 11 wherein the combination ofwavelengths is 1168 nm, 1458 nm, 1598 nm, 1718 nm, 1828 nm and 2048 nmand the biomechanical property is shear energy.
 14. A method accordingto claim 11 wherein the combination of wavelengths is 1268 nm, 1588 nm,1728 nm and 2278 nm and the biomechanical property is compressionenergy.
 15. A method according to claim 11 wherein the combination ofwavelengths is 1138 nm, 2018 nm, 2128 nm and 2408 nm and thebiomechanical property is comminution energy.
 16. A method fordetermining a biomechanical property of a feed, the biomechanicalproperty being one that reflects how easy it is for an animal to chewthe feed, the method comprising the steps of:(a) subjecting the feed toinfrared radiation to obtain spectral data; and (b) comparing thespectral data obtained in (a) with a calibration equation to determinethe biomechanical property;whereby, the biomechanical property of thefeed is determined on the basis of the bond energies of the chemicalconstituents of the feed.
 17. A method according to claim 16 wherein thecalibration equation is y₁ =19.95+10239.46 R₁₁₆₈ +3623.49 R₁₄₅₈ -4255.61R₁₅₉₈ -5319.88 R₁₇₁₈ +5148.38 R₁₈₂₈ +2452.05 R₂₀₄₈ and the biomechanicalproperty is shear energy (y₁).
 18. A method according to claim 16wherein the calibration equation is y₂ =231.42+18224.74 R₁₁₃₈ -4955.12R₂₀₁₈ -3005.37 R₂₁₂₈ +4290.18 R₂₄₀₈ and the biomechanical property iscomminution energy (y₂).
 19. A method according to claim 16 wherein thecalibration equation is y₃ =-0.71'911.04 R₁₂₆₈ +112.57 R₁₅₈₈ -79.48R₁₇₂₈ -28.02 R2278 and the biomechanical property is compression energy(y₃).
 20. A method according to claim 16 wherein the calibrationequation is determined from laboratory data establishing a correlationbetween reflectance and the biomechanical property.
 21. A methodaccording to claim 1 wherein an additional property of the feed is alsodetermined.
 22. A method according to claim 21 wherein the additionalproperty of the feed is digestibility of dry matter in vivo or in vitro.23. A method for determining feed quality, the method comprising thesteps of:(a) subjecting the feed to infrared radiation to obtainspectral data; (b) using the spectral data to determine a biomechanicalproperty of the feed, the biomechanical property being one that reflectshow easy it is for an animal to chew the feed; and (c) using thebiomechanical property obtained in step (b) to determine feedquality;whereby, the biomechanical property of the feed and thus feedquality is determined on the basis of the bond energies of the chemicalconstituents of the feed.
 24. A method according to claim 23 wherein thefeed quality is determined as a measure of voluntary feed consumption(VFC).
 25. A method according to claim 23 wherein the feed quality isdetermined as a measure of forage consumption constraint (FCC).
 26. Aspectrometer configured to carry out the method according to claim 1wherein the spectrometer is adapted to receive a sample of feed anddetermine a biomechanical property of the feed.
 27. A spectrometerconfigured to carry out the method according to claim 23 wherein thespectrometer is adapted to receive a sample of feed and determine thequality of the feed.
 28. A spectrometer according to claim 26 furthercomprising a data processing means for determining the biomechanicalproperty or the quality of the feed.